1)The answer is A. The short-run market supply curve is the horizontal summation of each firm's short-run supply curve. For instance, in a perfectly competitive firm, the supply curve slopes upward. Besides, it is relatively comparable to its curve on the monetary value that is supported by the principle of diminishing income. Therefore, any changes in the variable input costs employed by a firm will alter the short-run market supply curve and the supply on the MC curve. Furthermore, factors such as taxes, subsidies, technology, and other products' prices also affect the market supply curve of a firm.

2)Marginal propensity to consume (MPC) is the income increment that a consumer opts to spend in consumption rather than to save it. To attain marginal propensity to consume, the change in consumption is divided by the fluctuation in income.

A decrease in the marginal propensity to consume is a result of a rise in income. A rise in income heightens a consumer's ability to satisfy their needs and wants. Therefore, when an individual has more of their needs and wants satisfied the greatest tendency is to save more.

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