Cassie's Quilts Alters,reconstructs,and Restores Heirloom Quilts

Cassie's Quilts alters,reconstructs,and restores heirloom quilts.Cassie has just spent $800 purchasing,cleaning,and reconstructing an antique quilt which she expects to sell for $1,500 once she is finished.After having spent $800,Cassie discovers that she would need some special period fabric that would cost her $200 in material and time in order to complete the task.Alternatively,she can sell the quilt "as is" now for $900.What is the marginal cost of completing the task?

A) $200
B) $500
C) $1,000
D) $1,000 plus the value of her time