To Be a Successful Retailer, the Owner of the Artist

To be a successful retailer, the owner of The Artist Nook, a small artist supply store, would need to know:

A) what type of merchandise artists will want to buy.
B) how to correctly value the art supplies she sells.
C) the location of possible sources of art supplies.
D) what kind of product assortments would appeal to artists.
E) all of the above.