Rough endoplasmic reticulum is frequently observed in cells actively involved in the process of ____A____ and ____B____.

	A	B
1.	excretion	osmoregulation
2.	protein synthesis	secretion
3.	protein synthesis	cell lysis
4.	excretion	formation of glycolipids

Select the option that correctly identifies (A) and (B).

• A

  1

• B

  2

• C

  3

• D

  4