Which of the following is a suture material that is absorbable?

Catgut is indeed a type of absorbable suture material, historically derived from the intestines of sheep or goats. This material is designed to be broken down by the body over time, making it particularly useful for internal suturing in areas where removal might be difficult or for surgeries where sutures can be expected to dissolve naturally as the tissue heals.

In contrast, the other materials listed—silk, polyester, and nylon—are non-absorbable sutures. Silk is a natural suture that is often used for its ease of handling and knot security but requires removal after healing. Polyester and nylon are synthetic materials known for their strength and durability, also necessitating eventual removal from the body. Each of these sutures serves a specific purpose in surgical procedures, but their non-absorbable nature distinguishes them clearly from catgut.