Answer:
B. Muscle
Step-by-step explanation:
During embryonic development, three germ layers start to form in order to eventually go through the process of differentiation. These three layers are: the ectoderm - outer layer -, the mesoderm - middle layer -, and the endoderm - inner layer -.
The mesoderm gives rise to the both skeletal and smooth muscles, blood vessels, heart muscle, cartilage and joints, bone, cartilage, joints, connective tissue, blood cells, amongst other tissues.