Question

sinew means :
a part of the body, such as the heart, that carries out one or more functions
a band of tissue connecting a muscle to its bony attachment
an organism that benefits from another by causing damage
a main part of the central nervous system that conducts impulses

Explanation:

The word "sinew" refers to a tough band of fibrous connective - tissue that attaches muscle to bone.

Answer:

B. a band of tissue connecting a muscle to its bony attachment