Question

ribosomes are attached to the surface of the ______ er. rough smooth ridged rippled

Explanation:

Ribosomes are attached to the rough endoplasmic reticulum (ER). The rough ER appears "rough" because of the ribosomes on its surface, which are involved in protein - synthesis. Smooth ER lacks ribosomes. Ridged and rippled are not terms used to describe the ER in relation to ribosome attachment.

Answer:

A. rough