In some cities, many potters have been winning acclaim as artists.  But since pottery must be useful, potters must exercise their craft with an eye to the practical utility of their product.  For this reason, pottery is not an art.

Which of the following, is an assumption that supports drawing the conclusion above from the reason given for that conclusion?

A.  Some plates, bowl and vessels are made to be placed in museums where they will not be used by anyone.

B.  Some potters are more concerned than others with the practical utility of the products they produce.

C.  Potters should be more concerned with the practical utility of their products than they currently are.

D. Artists are not concerned with the monetary value of their products.

E. An object is not an art object if its maker pays attention to the objects’ practical utility.
 
The best answer is E.  The argument concludes that pottery is not an art because potters must consider the practical utility of their product.  If it is true that an object is not a work of art if its maker pays attention to the object’s practical utility, the conclusion is supported.