To this day, researchers and theorists debate whether bubonic plague caused The Black Death, a pandemic that swept the world in the middle of the fourteenth century.
A. whether
B. whether or not
C. about whether
D. as to whether
E. if
Can anyone tell me why this is the answer?
OA: A
My thoughts - I thought the idiom was whether or not
A. whether
B. whether or not
C. about whether
D. as to whether
E. if
Can anyone tell me why this is the answer?
OA: A
My thoughts - I thought the idiom was whether or not












