45. 下圖中植株必定是異型合子，何者正確？ (A)親代中的紫花植株 purple-flowered plants in the P generation (B)親代中的白花植株 white-flowered plants in the P generation (C)F1 中的紫花植株 purple-flowered plants in the F1 generation (D)F2 中的紫花植株 purple-flowered plants in the F2 generation