Which organelle is used to transport compounds throughout the cell?

A. Ribosome

B. Endoplasmic reticulum

C. Nucleus

D. Mitochondria

I'm pretty sure it's B, endoplasmic reticulum

Endoplasmic Reticulum

Explanation:

Vesicles are produced primarily in the membrane systems of the plasma membrane, endoplasmic reticulum and Golgi apparatus, they move throughout the cell along cytoplasmic filaments to discharge their contents to other organelles or outside the cell.