a few true or false questions about sequences/series and convergence

hi y'all, i'm having some real trouble with these T or F problems. I've tried to do them myself, but i have no idea if my answers are right. I would appreciate if you could tell me what you think the answers are so i can compare them to my own. Thanks!

a.) a sequence {a[subscript]n} only converges if

lim[subscript]n->infiniti a[subscript]n = 0

b.) if lim[subscraipt]n->infiniti (a[subscript]n / b[subscript]n) = 1 , where

a[subscript]n and b[subscript]n are positive for all n , and

[Epsilon]infinity,n=1 of b[subscript]n converges,

then [Epsilon]infinity,n=1 of a[subscript]n also converges.

c.) if lim[subscript]n->infiniti a[subscript]n = 0 ,

then [Epsilon]infinity,n=0 of a[subscript]n converges.

d.) If a series is absolutly convergent, then it is convergent.

e.) if a series is conditionaly convergent, then the terms of a series can be arranged so that the sum of ther series is pi.