Nonspecific permeases a. allow a variety of molecules to cross the cytoplasmic membrane. b. allow only water to cross the cytoplasmic membrane. c. are not used for passive transport. d. allow only one type of solute to pass through the membrane.

a. allow a variety of molecules to cross the cytoplasmic membrane

Explanation:

The cells have different molecules in its membrane. As a membrane the main function of it is to regulate the income and outcome of substances that the cell needs or the cell has like some wastes.

Some of these molecules can be some proteins like the permeases, that is going to  regulate the solutes that can enter the cell, but since they are non specific, that means that can not make the difference among one carbohydrate and another (as an example).

the answer to your question is:

c. complementary base-pairing