When the DeWitt Company Purchased a Large Piece of Machinery

When the DeWitt Company purchased a large piece of machinery from Moeller, the company's president paid a personal visit and stayed until the machine was up and running properly. This is an example of which guideline for selling to small business?

A) do provide after-sale support
B) do keep it simple
C) don't lump small and midsize businesses together
D) don't forget about direct contact
E) don't waste their time