The price of lemonade is $0.50; the price of popcorn is $1.00. If Fred has maximized his utility by purchasing lemonade and popcorn, his marginal rate of substitution will be:

A) 2 lemonades for each popcorn.
B) 1 lemonades for each popcorn.
C) 1/2 lemonade for each popcorn.
D) indeterminate unless more information on Fred's marginal utilities is provided.

Marginal Rate of Substitution

The rate at which a consumer is willing to substitute one good for another while maintaining the same level of utility.

Marginal Utilities

The supplementary utility or satisfaction received by using one more unit of a good or service.

Lemonade

A sweetened beverage made from lemon juice, water, and sugar, often associated with simple entrepreneurial ventures like lemonade stands.