Concept:Fibrous proteins are long, thread-like molecules that provide structural support and strength to tissues, whereas globular proteins are compact and roughly spherical.
Explanation:Myosin is a fibrous protein that forms the thick filaments in muscle fibres.
It binds with actin filaments to generate force and bring about muscle contraction.
This elongated, rod-like structure classifies myosin as a fibrous protein.
Now, consider the other options.
Legumelin is a globular protein found in plant seeds.
Insulin is a globular protein that acts as a hormone to regulate blood glucose levels.
Serum albumin is a globular protein present in blood plasma, responsible for transport of various substances.
Since legumelin, insulin, and serum albumin all have compact folded shapes, they are globular proteins.
Hence, among the given choices, only myosin is the fibrous protein.
Answer:Option B — Myosin.