Which of the following best describes the function of connective tissue?

a: Producing coagulation factors - This function is associated more with the liver, which produces various clotting factors involved in the coagulation process.

b. Destroying dying red blood cells: The spleen is primarily involved in the destruction of old or damaged red blood cells. It acts as a reservoir for blood, where it filters out old or abnormal red blood cells, recycling their components and removing any potentially harmful substances.

c: Producing leukocytes before birth - Leukocytes (white blood cells) are primarily produced in the bone marrow, not the spleen.

d: Storing glycogen - Glycogen storage is mainly associated with the liver and muscles, not the spleen.

a. Presence of calcium: Calcium does not directly stimulate the production of Vitamin D in the skin.

b. Exposure to ultraviolet light: UVB rays from sunlight stimulate the skin to produce Vitamin D3 (cholecalciferol).

c. Exposure to cold temperature: Cold temperature does not affect Vitamin D production.

d. Presence of parathyroid hormone: Parathyroid hormone helps regulate calcium levels and can stimulate the conversion of Vitamin D to its active form in the kidneys, but it does not stimulate its production in the skin.