Fact Pattern 11-1  Dave's Hobby Town and Estelle's Yarn Shoppe Are

Fact Pattern 11-1  Dave's Hobby Town and Estelle's Yarn Shoppe are adjacent stores with adjoining parking lots. Dave offers Estelle a discount on purchases from Dave's store if Estelle will not tow the cars of Dave's customers who park in Estelle's lot.
-Refer to Fact Pattern 11-1.Dave's discount is legally sufficient consideration​ 

A)  ​because it is a promise of something of value. 
B)  ​only if Dave adds a cash rebate. 
C)  ​only if Estelle uses it. 
D)  ​under no circumstances.