Indifference curves are convex to the origin due to the principle of diminishing marginal rate of substitution. This occurs because goods are generally imperfect substitutes for one another. As a consumer acquires more of one good, they are willing to give up progressively smaller amounts of the other good to maintain the same level of total utility, resulting in the characteristic bowed-inward shape of the curve.

The law of demand (A) holds true for normal goods. The price effect is indeed the sum of the substitution effect (which is always negative, meaning price and quantity move in opposite directions) and the income effect. For normal goods, the income effect reinforces the substitution effect, leading to an inverse price-quantity relationship.

The correct associations are: Revealed Preference Theory (Samuelson), Cardinal Utility Analysis (Marshall), Ordinal Utility Analysis (Hicks), and Compensatory Demand Curve (Slutsky). Matching these gives a-4, b-1, c-2, d-3. These economists are central figures in the development of consumer choice theory and demand analysis within microeconomics.

Statement A correctly describes the Law of Diminishing Marginal Utility. Statement B correctly describes the relationship between Marginal Product (MP) and Total Product (TP) under the Law of Variable Proportions, where a declining MP indicates that TP is increasing at a decreasing rate. Since both statements are accurate, 'None of the above' is the correct choice.

Marginal utility intersects average utility at the point where average utility is at its maximum. When marginal utility is greater than average utility, the average is rising; when marginal utility is less than average utility, the average is falling. Therefore, the equality occurs precisely at the peak of the average utility curve.

Revealed preference theory relies on axioms like consistency and transitivity to infer consumer preferences from observed choices. While 'weak ordering' is a mathematical property related to preferences, it is often distinguished from the core behavioral axioms of revealed preference analysis.

Consumer goods are defined as products that are purchased by individuals for final consumption rather than for use in the production of other goods. These goods directly satisfy human wants. They are distinct from capital goods, which are used to produce other goods and services. The definition provided in option B accurately reflects the economic classification of consumer goods.

A budget line represents the combinations of two goods a consumer can afford given their income and the prices of the goods. If the consumer's budget increases while prices remain constant, the consumer can afford more of both goods. This causes the budget line to shift outward, away from the origin, parallel to the original line.

The Marginal Rate of Substitution (MRS) is the rate at which a consumer is willing to give up one good in exchange for another while maintaining the same level of utility. Graphically, this is represented by the absolute value of the slope of the indifference curve at any given point.

According to the law of diminishing marginal utility, total utility increases as more units are consumed until it reaches a peak. At this saturation point, the additional utility gained from the last unit (marginal utility) is zero. Beyond this point, total utility begins to decline.