Yosef received a sales message in the form of a letter. In this letter, a company offered a four-year warranty on a dishwasher, but failed to mention that the cost of the warranty will significantly increase after one year. This is an example of which of the following?

A. sending spam

B. using the common-ground technique

C. sending a solicited proposal

D. misrepresenting a product

E. disguising a sales message