The given sentence is in the passive voice: ``Then her face was bowed." In passive voice, the subject receives the action, whereas in active voice, the subject performs the action.
- Option A: ``Then she was being bowed her face" is incorrect as it does not form a proper structure in passive or active voice. The use of ``was being bowed" is not appropriate here.
- Option B: ``Her face was bowed by them" is correct in passive voice but does not express the active voice as required by the question.
- Option C: ``Then she bowed her face" is the correct transformation into the active voice. Here, the subject ``she" performs the action of bowing her face.
- Option D: ``Then her face has been bowed" is in present perfect passive, which is not the correct tense for the given sentence. Thus, the correct answer is Option C.
If the roots of the quadratic equation \( ax^2 + bx + c = 0 \) are real and equal, then: