Sarah baked 78 cupcakes for the bake sale. Gabby baked 45 cupcakes for the bake sale. 93 cupcakes were sold at the bake sale. Which is a way to find the number of cupcakes NOT sold?

A.Add 78,45,and 93.
B. Find the sum of 78 and 45. Then subtract 93.
C. Find the difference between 78 and 42. Then add 93
D. Find the sum of 93 and 45. Then subtract 78.

is the answer B.