Which statement would be true of a membrane-bound protein that works in conjunction with a sodium–potassium pump during secondary active transport?
a. it will be able to transport an ion in both directions across the cell membrane and a small molecule in one direction.
b. it will block a small molecule from moving across the cell membrane in response to an increase in concentration of an ion in the external environment.
c. it will move a small molecule across the cell membrane in response to a build-up in concentration of the molecule in the external environment.
d. its conformation will change when both an ion and a small molecule bind to it.

The correct answer is option d. "Its conformation will change when both an ion and a small molecule bind to it".

Explanation:

The secondary active transport is a form of active transport at which a ion (typically Na+ or H+)  is transferred down its electrochemical gradient to the uphill movement of another molecule. Secondary active transport takes place by the conjunctive work of membrane-bound proteins and sodium–potassium pumps. During secondary active transport, both of these proteins change its conformation when an ion and a small molecule bind to it. This change in conformation makes possible that the ions and the small molecules pass through the membrane.

true is the final answer!

c. the initial amount of money placed in the savings account