求NN解答一道OG13中的题目！！

kittyljy

Which of the following most logicallycompletes the argument?

By competing with rodents for seeds, blackants help control rodent populations that pose a public health risk. However, avery aggressive species of black ant, the Loma ant, which has recently invadeda certain region, has a venomous sting that is often fatal to humans. Therefore,the planned introduction into that region of ant flies, which prey on Lomaants, would benefit public health, since.

(A) ant flies do not attack blackants other than Loma ants

(B) Loma ants are less effectivethan many bird species in competing with rodents for seeds

(C)  certain other species of blackants are more effective than ants in competing with rodents for seeds

(D)the sting of Loma ants can alsobe fatal to rodents

(E)   some pesticides that could beused to control Loma ants are harmful to the environment

为什么选A？？？疑惑！！！！