Hey can you me posted picture of question: )

The product of a and b appears as a constant term in the trinomial. This can be seen below:

(x + a)(x + b)
= x² + xa + xb + ab
= x² + (a+b)x + ab

a and b both are constants, they are only being multiplied once to each other, so their product also results in a constant. 

The correct answer to this question is option B

The product of a and b would be the constant term of the trinomial