Regarding 1,25 dihydroxycholecalciferol (calcitriol):

• A. it is formed by the action of sunlight on pre vitamin D3
• B. it exerts its action via stimulation of adenylcyclase
• C. it decreases calcium reabsorption from kidneys
• D. its formation is increased with elevated plasma Ca++ levels
• E. it causes increased formation of calbindin-D proteins