Smooth muscles are spindle-shaped and are under involuntary control. They are seen in the internal organs such as the blood vessels, iris and the lung bronchi. In the blood vessels, they enable the blood flow. In iris, they increase the pupil size in the presence of bright light. They help in lung contraction and relaxation due to their presence in bronchioles. Thus the correct answer is option D.

Muscles contract via the action of proteins actin and myosin. Both these proteins are present as microfilaments. Actin forms the thin filaments of muscle cells and myosin forms the thick filaments.

"Myo" refers to "Muscles". Myology is the study of the muscular system, including the study of the structure, function, and diseases of muscle.

Areolar Tissue is a common form of loose connective tissue. Areolar tissue is found in many locations around the body.

Epithelial tissues form the covering of all body surfaces, lines body cavities and hollow organs, and are the major tissue in glands. 

Our outer layer of skin is made up of epithelial tissues. The epidermis is composed of the outermost layers of cells in the skin.

Cell junctions are proteins that connect the cytoplasmic content of adjacent cells, they form a barrier between two cells and also hold or adhere cell together or with the extracellular matrix. these are abundant in epithelial tissue.

Each fasciculus (bundle of muscle fibres) is surrounded by a connective tissue sheath called perimysium. Epithelial tissues arise from all the three primary germ layers of the embryo i.e., ectoderm, mesoderm and endoderm.