Which of the following statements about cotransport of solutes across a membrane is correct?

• A. Cotransport involves the hydrolysis of ATP by the transporting protein.
• B. A cotransport protein is most commonly an ion channel.
• C. The sodium-potassium pump is an example of a cotransport protein.
• D. In cotransport, both solutes that are being transported are moving down their chemical gradients.
• E. Cotransport proteins allow a single ATP-powered pump to drive the active transport of many different solutes.