Place in order the following events of receptor-mediated endocytosis.
(1) Clathrin coat disappears.
(2) Receptors collect in a coated pit covered with clathrin on the cytoplasmic side.
(3) Receptors recognize and bind specific molecules.
(4) Endocytic vesicle may fuse with lysosome whereas receptors are recycled to the cell surface.
(5) Pits deepen and pinch free of plasma membrane to form endocytic vesicles.
a. 4,1,2,5,3
b. 2,1,3,5,4
c. 3,2,5,1,4
d. 4,1,5,2,3
e. 3,1,2,4,5