In case of positive externalities, the market equilibrium output is greater than the socially optimal output

Its lunch time, you are hungry and would like to have some pizza. By the law of diminishing marginal value,

a. you would pay more for your first slice of pizza than your second b. you would pay more for your second slice of pizza than your first c. you would pay an equal amount of money for both the slices since they are identical d. none of the above

Which of the following do most economists consider to be the most basic measure of a nation's international transactions?

a. balance on current account b. balance on capital account c. balance of merchandise trade d. balance on long-term capital