Which one of the following parts of human alimentary canal can be of maximum length?

Which one of the following salts is found in maximum amount in the human bones?

A patient’s abdomen (alimentary canal) can be examined by X-ray after administering which one of the following metal salts in the patient’s meal?

Which one of the following body parts/organs of the human body does not have smooth muscles?

Which of the following is the smallest bone in the human body?

Which one of the following statements best describes the role of B cells and T cells in the human body?