Sets Operations

Let $A$ , $B$ and $C$ be any three sets such that $A-B=C$ ; then which of the following statement(s) is/are correct?

1. $A$ is the union of $B$ and $C$
2. $C$ is always a proper subset of $A$
3. $C$ is the compliment of $B$

ANSWER FORMATE: Enter the sum of the serial numbers as answer. For example, if all three statements are correct then the answer is: $1+2+3=6$ .