Let me try to address the various options.
a) Mr. Gordons comic book collection grew extensively with it’s
The comic book collection mentioned here clearly belongs to Mr Gordon and hence requires the use of an apostrophe - "Mr Gordon's comic book collection...". Eliminate.b) Mr. Gordon’s comic book collection it grew extensively with the The "it" after "collection" is redundant.
The verb directly follows the noun it is associated with and the use of a pronoun is redundant. Eliminate.c) Mr. Gordons comic book collection grew extensively with its
The comic book collection mentioned here clearly belongs to Mr Gordon and hence requires the use of an apostrophe - "Mr Gordon's comic book collection...". Eliminate.d) Mr. Gordon’s comic book collection grew extensively with its
Correct answer.e) The collection of Mr. Gordon’s comics grew extensively because of it’s
Here, "addition" represents a quality/action of the collection. The correct usage would be "its" at the end - "it's" expands to "it is" and is incorrect here. Eliminate.Hope this helps.