Answer:
B
Step-by-step explanation:
The answer is
2/5 = 0.4
Because
2/5 2 divide 5 = 0.4
The interest rate is 4<span />
Looks like you have most of the details already, but you're missing one crucial piece.
is parameterized by

for
and
, and a normal vector to this surface is

with norm

So the integral of
is
