Which pair of complex factors results in a real-number product?

a. 15(–15i)

b. 3i(1-3i)

c. (8 + 20i)(–8 – 20i)

d. (4+7i)(4-7i)

we will proceed to solve each case to determine the solution of the problem

we know that

case A.

The result of case A is not a real number product

case B.

The result of case B is not a real number product

case C.

The result of case C is not a real number product

case D.

The result of case D is a real number product

therefore

the answer is the option

what?

step-by-step explanation:

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