nahid078 wrote:Mary received nine reports from her students after the midterm, using it to to help calculate the overall grades.

(A) Mary received nine reports from her students after the midterm, using it to help calculate

(B) Mary received nine reports from her students after the midterm, and used it to help in calculating

(C) Mary used the nine reports she received from her students after the midterm to help calculate

(D) Mary's nine reports she received from her students after the midterm were used to help her in calculating

(E) Receiving nine reports from her students after the midterm, Mary used them to help calculate

Options A and B
"it" cannot refer to the plural noun "nine reports".

Option A -
the modifier ", using it to calculate the overall grades." does not make sense because it is neither an effect nor does it describe "HOW" she received reports from her students.

Option B -
", and used it to help ..." - we do not generally use commas to separate two phrases.

Option D - "were used ..." - by whom? Not clear.
Also, this says "Mary's nine reports" - not the intended meaning.
the pronoun "she" does not refer to anything.

Option E -
note that "-ing" modifiers happen in the same time frame as the main clause. Here, "receiving" and "calculation of grades" seem to happen at the same time. Illogical.
Clearly, she received the reports first and then those reports were used to calculate the grades.