Which letter from the following image represents the white blood cell subtype that includes B and T cells?

A. This allows for rapid exchange of oxygen and nutrients: Capillaries have thin walls (one cell thick) to facilitate the rapid diffusion of gases (oxygen and carbon dioxide), nutrients, and waste products between blood and tissues.

B. This allows for red blood cell formation to occur: Red blood cells are formed in the bone marrow, not in capillaries.

C. There is no blood pressure within the capillaries: There is still blood pressure within capillaries, although it is lower than in arteries, so this is incorrect.

D. Blood does not travel through capillaries: Blood does indeed travel through capillaries as part of the circulatory system.

A. Red blood cells are removed from the blood: Red blood cells are too large to be filtered at the glomerulus. Only plasma and small molecules pass through.

B. Water is taken out of the pre-formed urine: This happens in later parts of the nephron, such as the collecting ducts, not at the glomerulus.

C. Most of the water is removed from the blood: The glomerulus filters blood, removing water, ions, glucose, and waste products from the bloodstream to form the filtrate.

D. Nutrients are released to the kidneys: Nutrients are filtered into the renal tubules and then reabsorbed, but they are not "released" to the kidneys.