Jenny’s dream was to become the first female mayor of her home city

(A) while running in the mayoral election, cancer was detected and another candidate had to be chosen.

(B) while running in the mayoral election, Jenny’s cancer was detected and another candidate had to be chosen.

(C) while running in the mayoral election, cancer was detected and another candidate was chosen.

(D) while running in the mayoral election, the cancer was detected and another candidate was chosen.

(E) while running in the mayoral election, a cancer was detected and another candidate was chosen.

Option A, C, D, and E have Modifier Error; The subordinating clause while running in the mayoral election incorrectly modifies cancer rather than Jenny. In a perfect world, even Option B must be incorrect because we must have Jenny instead of Jenny's Cancer. However, Option B is the best option. Questions such as this one ideally do not appear on the actual GMAT.