Exocytosis releases substances outside the cell via vesicle fusion

Steps:

• Examine diagram: substance Z is inside a vesicle near the cell membrane.
• Vesicle fuses with membrane, opening to exterior.
• Substance Z moves out of cell.
• Process matches export mechanism.

Why B is correct:

• Exocytosis expels cellular products by merging vesicles with plasma membrane, as defined in cell biology.

Why the others are wrong:

• A. Endocytosis imports substances into the cell via vesicle formation.
• C. Phagocytosis engulfs solid particles through endocytosis.
• D. Pinocytosis absorbs extracellular fluid nonspecifically via endocytosis.

Final answer: B