Answer: The correct option is
(C) 56-5i.
Step-by-step explanation: We are given to simplify the following product of complex numbers :

To simplify the given product, we must multiply each term of the first factor each term of the second factor and will be using the following vale of i :

From (i), we get

Thus, the required simplified form is 56-5i.
Option (C) is CORRECT.