Interpret the algebraic expression corresponding to the given context.
 Sandi buys 3 fewer packages of pencils than p packages of pens. Pencils costs $2.75 per
 package and pens costs $3 per package. What does the expression 3p + 2.75(p - 3)
 represent?
 The expression 3p +2.75(p - 3) represent the 
 A. Cost of pencils
 B.numbers of pens and pencils 
 C. Cost of pens 
 D. Total cost of pens and pencils