This is just a "look and see" problem. There's nothing to do but just observe
that in this:
(3j-5)[3(2j+7)-4k(6j-8)]
what I have colored red, namely (3j-5)
is multiplied by what I have colored purple, namely, [3(2j+7)-4k(6j-8)]
Factors are expressions that are multiplied, and whar I have colored red
is indeed a factor, and it is listed as choice (d).
This was just too easy!
Edwin