the correct question in the attached figure
case A) an=2^(n-1)
for n=8
a8=2^(8-1)-----> a8=2^7----> a8=128
the answer case A) is
a8=128
case B) an=7
then for n=8
a8=7
the answer case B) is
a8=7
case C) an=1+(-1)^n
for n=8
a8=1+(-1)^8----> a8=1+1----> a8=2
the answer case C) is
a8=2
case D)an=-(-2)^n
for n=8
a8=-(-2)^8----> a8=-256
the answer case D) is
a8=-256