The correct answer is (d) 8.79 V
To elaborate: The generated e.m.f can be calculated using the formula Eb = Φ×Z×N×P÷60×A, Φ represent flux per pole, Z represents the total number of conductors, P represents the number of poles, A represents the number of parallel paths, N represents speed in rpm. Eb = 4×2×3000×2÷60×91 = 8.79 V.