I came across this question online.

The impostor eluded detection for so long because she conducted herself as though she were a licensed practitioner.

A. as though she were a licensed practitioner.
B. as though she was a licensed practitioner.
C. like she was a licensed practitioner.
D. like as if she was a licensed practitioner.
E. as if she was a practitioner with a license


The OA is A. Explanation needed. Thanks in advance