Hi there,
Some scholars assert that
the foundation of Slavonic literature was as a result of the linguistic contributions by two brothers in ninth-century Great Moravia, Cyril and Methodius, who are credited with inventing the Glagolitic alphabet.
Meaning Analysis:Linguistic contributions of two brothers resulted in the foundation of Slavonic literature.
Error Analysis:The phrases “Slavonic literature was as a result” is not idiomatic. We can simply say that “Slavonic literature was a result”.
PoE:A. the foundation of Slavonic literature was as a result of the linguistic contributions by:
Incorrect for the reason stated above.
B. Slavonic literature’s founding was mainly contributed by the linguistic influence of:
Incorrect. 1. Use of “proper” noun form is always better than the “ing” noun from of a worm. “founding” should be “foundation”.
2. Per this choice, the foundation was contributed by the “influence” and not the two brothers.
C. Slavonic literature was founded as a result of the linguistic contributions of:
Correct.D. the foundation of Slavonic literature stems from linguistic contributions made by:
Incorrect. Use of simple present is incorrect.
E. the founding of Slavonic literature is derived from linguistic contributions by:
Incorrect.1. Use of “founding” is not correct.
2. Use of simple present tense is incorrect.
Hope this helps.

Thanks.
Shraddha