Final answer:
B. Retrograde; Clathrin
CCV travels in a retrograde direction and is coated by clathrin, not COPI or COPII proteins.
Step-by-step explanation:
The CCV (clathrin-coated vesicle) typically follows a retrograde path and is coated by clathrin. During retrograde transport, vesicles move from the plasma membrane and endosomes back toward the Golgi apparatus and the endoplasmic reticulum (ER).
Clathrin is a protein that plays a crucial role in shaping rounded vesicles in the cytoplasm and is involved in various processes, including receptor-mediated endocytosis, where it forms clathrin-coated pits that bud off to become clathrin-coated vesicles.
In contrast, COPI and COPII proteins are involved in different types of vesicular transport; COPII is typically associated with anterograde transport from the ER to the Golgi apparatus.