Which of the following is a semisynthetic polymer?
A.Rubber
B.Silk
C.Wool
D.Cellulose nitrate

Hint:Semisynthetic polymers are mostly derived from naturally occurring polymers by chemical modifications. Now find which polymer among these options is a semisynthetic polymer.

Complete step by step answer:
- You should know that the two major classes of polymers include synthetic polymers and natural polymers.
-In addition to these two major groups, there are other types of materials in which the original polymer is a natural product but is chemically and/or physically treated.
Perhaps the “semi-synthetic polymers” that was stated in the question refers to this kind of polymers.
-Cellulose acetate is an example of a thermoplastic material that is produced from cellulose (a natural polymer), rather than through the polymerization reaction of a monomer. There is no polymerization reaction for the production process of cellulose nitrate material and other chemical derivatives of cellulose. Therefore, we can consider these as semi-synthetic or regenerated polymers.
-Cellulose diacetate polymers are formed on acetylation of cellulose with acetic anhydride in the presence of sulphuric acid. It is used in making threads and materials like film glasses etc.

Therefore, the correct answer is option D.

Note:
Rubber, Silk, and wool are examples of natural polymers because they are found in plants and animals.
Vulcanized rubber is also an example of semisynthetic polymers used in making tires etc. gun cotton which is cellulose nitrate used in making explosives.