The amount of simple interest during ‘n’ interest period is (where, i = interest rate based on the length of one interest period, p = principal) ?

The amount of simple interest during ‘n’ interest period is (where, i = interest rate based on the length of one interest period, p = principal) ?

A. p.i.n.
B. p(1 + i.n)
C. p(1 + i)n
D. p(1 – i.n)