The answer is going to be D -6
r=1/2
Sn=a(1-r^n)/1-r
S(infinite sign) = a/1-r
S(infinite sign) = -3/1-1/2
S(infinite sign) = -3/1/2
S(infinite sign) = -3/1/1*2/2-1/2
S(infinite sign) = -3/1*2/2-1/2
S(infinite sign) = -3(3*2)
S(infinite sign) = -1*6
S(infinite sign) = -6