a) To separate the fibers
b) To produce a well cooked pulp
c) To bleach the pulp
d) To increase the strength of the pulp

Answer: b
Explanation: The primary function of digestion is to produce a well cooked pulp, free from the non-cellulosic portions of the wood (i.e., lignin and to a certain extent hemicelluloses). It’s other functions are- to achieve a maximum yield of raw material (i.e., pulp from wood) commensurate with pulp quality and to ensure a constant supply of pulp of the correct quality.