SDCAR2010【逻辑入门】（八）Assumptions

wsyzzydy

20. In recent years, many cabinetmakers have been winning acclaim as artists. But since furniture must be useful, cabinetmakers must exercise their craft with an eye to the practical utility of their product. For this reason, cabinetmaking is not art.
Which of the following is an assumption that supports drawing the conclusion above from the reason given for that conclusion?
(A) Some furniture is made to be placed in museums, where it will not be used by anyone.
(B) Some cabinetmakers are more concerned than others with the practical utility of the products they produce.
(C) Cabinetmakers should be more concerned with the practical utility of their products than they currently are.
(D) An object is not an art object if its maker pays attention to the object’s practical utility.
(E) Artists are not concerned with the monetary value of their products.

请问下这种是necessary 还是sufficient？？
我觉得是sufficient，但是取非D也可削弱，解释答案。

wsyzzydy

thanks. your method really makes the assumption question simple~