Mark and Ann together were allocated n boxes of cookies to sell for a club project. Mark sold 9 boxes less than n and Ann sold 2 boxes less than n. If Mark and Ann have each sold at least one box of cookies, but together they have sold less than n boxes, what is the value of n? Select the correct option:
A) 9
B) 10
C) 11
D) 12
E) 13

Rationale: "if n = 10 mark sold 1 box and ann sold 8 boxes total 9 < 10 answer : b"
Answer: B