Help in finding the sum of the series!

Find the sum of: -

A) (-2/3)^k when K goes from 1 to infinity...I got (3/5)!

B) 2^k / [3^(2k+1) when k goes from 0 to infinity...I got (9/7)!

c) 1 / k(k+1)...when K goes from 1 to infinity...I got (1)

d) 1 / k(k+2)...when K goes from 1 to infinity...I am not sure how to split this term in two different term.

I have got the solution for starting three, but I am not sure if I have done it right or not. I used the geometric series formula (1/1-r) in order to solve them.

Please help me making it sure!

Thanks!