lsat 2-4-15

15.   In a large residential building, there is a rule that no pets are allowed. A group of pet lovers tried to change that rule but failed. The rule-changing procedure outlined in the building’s regulations states that only if a group of tenants can obtain the signatures of 10 percent of the tenants on a petition to change a rule will the proposed change be put to a majority vote of all the tenants in the building. It follows that the pet lovers were voted down on their proposal by the majority of the tenants.

The argument depends on which one of the following assumptions?

(A) The pet lovers succeeded in obtaining the signatures of 10 percent of the tenants on their petition.

(B) The signatures of less than 10 percent of the tenants were obtained on the pet lovers’ petition.

(C) Ninety percent of the tenants are against changing the rule forbidding pets.

(D) The support of 10 percent of the tenants for a rule change ensures that the rule change will be adopted.

(E) The failure of the pet lovers to obtain the signatures of 10 percent of the tenants on their petition for a rule change ensures that the rule change will be voted down by a majority of the tenants.

答案是a，请教大家了~~

谢谢啦~~