The correct option is B myosin
Contractile proteins are proteins that bring about muscle contraction in the skeletal muscles. It includes actin and myosin.
Actin and myosin are arranged as filaments called myofilaments. These are of two types: thin and thick filaments.
The thin filament consists of the proteins actin, troponin, and tropomyosin, whereas the thick filament consists of myosin.
The actin protein that makes up most of the thin filament is filamentous in form and hence is called F actin. F actin is a polymer of G (globular) actin monomers.