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Option (3) is correct.
Explanation:
(a) Marginal Rate of Substitution (MRS): It refers to the number of units of good Y which the consumer is willing to gain for an additional unit of good X.
(b) Consumer's Bundle: It is a qualitative combination of three goods which can be purchased by a consumer from his given expenses at given prices.
(c) Budget set: It is quantitative combination of those bundles which a consumer can purchase from his given income at prevailing market prices.
(d) Consumer Budget: It states the real employment of the consumer from which he can purchase certain qualitative bundles of three goods at given price.

By: Parvesh Mehta