Although Linus Pauling was well-known for his work as an educator, author, and peace activist, his work in chemistry, specifically the nature of the chemical bond, which had begun in the 1920s, gained the most recognition in that it earned him both the Irving Langmuir Award as well as the Nobel Prize in Chemistry.

A. which had begun in the 1920s, gained the most recognition in that it earned him both the Irving Langmuir Award as well as the Nobel Prize in Chemistry
B. begun in the 1920s, gained the most recognition, earning him both the Irving Langmuir Award and the Nobel Prize in Chemistry
C. begun in the 1920s, gaining the most recognition by earning him both the Irving Langmuir Award and the Nobel Prize in Chemistry
D. had begun in the 1920s and which, earning him both the Irving Langmuir Award and the Nobel Prize in Chemistry, gained the most recognition
E. had begun in the 1920s, earning him both the Irving Langmuir Award as well as the Nobel Prize in Chemistry, and gaining the most recognition


OA B

Source: EMPOWERgmat