Question

what do the pharyngeal arches in vertebrate embryos contain? a complex collection of nerves, muscles, and connective tissue. only muscles that later become bones. only nerves connected to the brain. blood vessels but no structural tissues.

Explanation:

Pharyngeal arches in vertebrate embryos contain a complex mix of nerves, muscles, and connective - tissue which contribute to the development of various structures in the head and neck.

Answer:

A. A complex collection of nerves, muscles, and connective tissue.