Which of the following receptors allow ions such as Na+, K+, and Ca+2, etc. to pass through the membrane in response to the binding of a chemical messenger?

Which of the following receptors allow ions such as Na+, K+, and Ca+2,

1.	Which of the following receptors allow ions such as Na+, K+, and Ca+2, etc. to pass through the membrane in response to the binding of a chemical messenger?
A.	Sodium/glucose co-transporter
B.	GLUT 1
C.	Na<sup>+</sup>/K<sup>+</sup> ATPase
D.	Ionotropic receptors
Answer» E.