The corporate strategic plan included provisions to expand operations, manufacturing would be streamlined, and introduce a new line of lower-priced items.

(A) expand operations, manufacturing would be streamlined, and include a new line of lower-priced items.
(B) create expanded operations, work to streamline manufacturing, and include a new line of lower-priced items.
(C) expanded operations, streamlined manufacturing, and introduced a new line of lower-priced items.
(D) expand operations, streamline manufacturing, and introduce a new line of lower-priced items.
(E) expand operations, streamline manufacturing, and a new line of lower priced items.

Right off the bat, we can eliminate C because "provisions to expanded operations" makes zero grammatical sense.

We have a list of provisions that are part of a plan. Whenever we have a list, we want the parts of the list to be grammatically parallel. So we can eliminate any options where the list items aren't parallel:

A) expand ... manufacturing ... include --> verb, noun, verb: Eliminate
B) create ... work ... include --> verb, verb, verb: Keep
D) expand ... streamline ... introduce --> verb, verb, verb: Keep
E) expand ... streamline ... a new line --> verb, verb, noun: Eliminate

So we're down to B and D. Looking at the two answers, we see they say approximately the same thing, just that B says it in far more words. So we choose D for concision reasons.