Few pointers to be noted::
--> Data vs Information: uncountable nouns like this (including information, administration, management, advice, accommodation) are singular with no plural form.
The word data is plural.-->
Do not strike out an answer choice just because it contains "being". The intended meaning is more important
-->
Pronoun is not ambiguous if the action performed by a pronoun can only be done by 1 antecedent. If any answer choice adds more clarity to the pronoun-antecedent, then that answer choice shall be preferred, provided the rest all are the same in the two answer choices.
I take the intended meaning of the activity as in the present continuous tense form. "Might lie" and "upcoming decision" give me two such indicators. Since the complete data has not been collected completely, hence the author itself is not sure of the gravity of influence or importance here. Going by this sense, (A) makes better sense.
In (B) an important point to note is the absence of the pronoun. Rather than removing the pronoun ambiguity by adding a noun here, the answer choice has added more ambiguity by removing the pronoun. This answer choice does not answer 'whose greatest importance'. It may sound a bit of the ellipsis here, but I do not see it that way.
Request to kindly correct me wherever I am wrong !!