A cylinder is of height h and base radius r. If t denotes the total surface area and v its volume, then $$\frac{t}{2v} =$$

A

$$\frac{2}{r} + \frac{2}{h}$$

B

$$\frac{3}{r} + \frac{3}{h}$$

C

$$\frac{1}{2r} + \frac{1}{2h}$$

D

$$\frac{1}{r} + \frac{1}{h}$$