【單選題】每題 2 分，共計 40 分，答錯 1 題倒扣 0.5 分，倒扣至本大題零分為止，未作答，不給分亦不扣分。61. A student measured the optical activity of an unknown sugar at two different concentrations. The results of hismeasurements are shown below. Given that the sample cell had a path length of 10.0 cm, calculate the specific rotationfor the unknown sugar.concentration                               observed rotation2.00 g sugar in 10.0 mL water              +159.1°  5.00 g sugar in 10.0 mL water              +127.8° 
(A) -10.5°
(B) +25.6°
(C) +79.5°
(D) -104.5°
(E) +256.2°