Which of the following should be held constant when calculating an income elasticity of demand?

To counter parents' concerns about fast foods and childhood obesity, McDonalds considered:

A) a variety of menu items such as milk shakes and candy. B) a variety of menu items such as apple slices, fruit juices, peanut butter and jelly sandwiches, and carrot sticks. C) not changing the menu. D) all of the above.

If a bank needs to acquire funds quickly to meet an unexpected deposit outflow, the bank could

A) borrow from another bank in the federal funds market. B) buy U.S. Treasury bills. C) increase loans. D) buy corporate bonds.