求解释逻辑10套中的一题

gunxueqiucjw

4.Although spinach is rich in calcium, it also contains large amounts of oxalic acid, a substance that greatly impedes calcium absorption by the body. Therefore, other calcium-containing foods must be eaten either instead of or in addition to spinach if a person is to be sure of getting enough calcium.
Which of the following, if true, most seriously weakens the argu-ment above?
(A)Rice, which does not contain calcium, counteracts the effects of oxalic acid on calcium absorption.
(B) Dairy products, which contain even more calcium than spinach does, are often eaten by people who eat spinach on a regularbasis.
(C) Neither the calcium nor the oxalic acid in spinach is destroyed when spinach is cooked.
(D) Many leafy green vegetables other than spinach that are rich in calcium also contain high concentrations of oxalic acid.
(E) Oxalic acid has little effect on the body's ability to

谁能解释D选项为什么不对