Reed Agrees to Sell His Sports Equipment Store to Taylor

Reed agrees to sell his Sports Equipment store to Taylor. As part of the sale, Reed promises not to open a similar, competing store anywhere. This promise is most likely

A) invalid because it is part of a sale of an ongoing business.
B) invalid because of the unreasonable terms of area and time.
C) valid because it is part of a sale of an ongoing business.
D) valid if both parties are justifiably ignorant of the facts.