Diminishing marginal utility

a. implies that increases in income will give less utility to a rich person than to a poor person.

b. implies that a given amount of added income would tend to provide less utility to a given individual at higher levels of income than at lower levels of income.

c. implies that income redistribution from higher- to lower-income people will give more utility to the lower-income people than it will take from the higher-income people.

d. implies that all of the above are true.