B is the answer for the problem
The phrase helps to conclude the text and does not add to the writing. ... The phrase adds a specific detail about time that is relevant to the text's topic. The phrase helps to introduce the text's topic by providing a direct object.
#2 is correct.
Problems with the others:
#1 - best is a superlative (used to compare more than three or more things)
#3 - best is the greatest something can be so you cannot have more of it
#4 - you either use "more" OR "better" because "more better" would be just be the best
