[单选题]
3. Which of the following p/ u(sovqzg4ue1h.o-m: xs ky6oints fa ic.0k;knn1 is not correct about a transmembrane receptor?
A. It binds to a specific ligand.
B. It is a protein molecule.
C. It has hydrophobic and hydrophilic regions in the molecule.
D. The same receptors are found in all cells
