Is it B?

I need to understand the meaning and usage of
in addition to = along with X Y is also satisfied
Besides - Not only X but also Y is satisfied.

I would bet my money on E.. A, B & C are out since "It" or "Its" refers to something singular whereas the phrase after the semi colon refers to "brewed leaves of Camellia" which is plural. The decision is between D and E. E seems concise and idiomatic. And pluralism is maintained among "preventing, inhibiting & reducing."

OA E ..isnt the answer related to parallelism..i think e is correct because it is parallel to the second part of the sentence.

The health benefits of tea have been the subject of much research;in addition to its possibillities for preventing and inhibiting some forms of cancer,the brewed leaves of Camellia Sinesis may also play a role in reducing the risk of heart disease and stroke

A)in addition to its possibillities for preventing and inhibiting
Its is wrong here...because its(singular) is refering to brewed leaves(plural).

B)same as above.

c)same as above. It is refering to brewed leaves.

D)besides the possible preventing and inhibiting of
possible preventing and inhibiting of is wrong. The correct usage is possibility of preventing and inhibiting

E)besides possibly preventing or inhibiting
Correct choice... Ing modifier acts a noun: besides...noun....noun/phrase/clause

Yup I agree with navami on his explanation ........

It should be E.

This question will be cake if you find out that prevent(ing) OR/AND inhibit(ing)

here we must use OR , not AND why ?

because preventing , inhibiting can't be done at the same time.
Tea either inhibit disease if its already there OR prevent it but not both at the same time.

Hence A C D out

in E "preventing or inhibiting" goes smoothly with reducing

E Wins

HTH..

Sumit