Final answer:
Simple cuboidal epithelium, option a, lines kidney tubules, and smooth muscle is responsible for contractions of the digestive tract and arteries.
Step-by-step explanation:
The type of epithelial tissue that lines kidney tubules is simple cuboidal epithelium. Simple cuboidal epithelial cells have a cuboidal shape and are involved in filtering blood in the kidney. They are responsible for reabsorbing important substances from the filtrate and secreting others into the filtrate to form urine.
The type of muscle responsible for contractions of the digestive tract and arteries is smooth muscle. Smooth muscles are involuntary muscles that are found in the walls of organs and blood vessels. They contract and relax to help move food through the digestive tract and regulate blood flow in arteries.
Therefore, the correct option is a) Simple cuboidal epithelium.