Let A and $B$ be two sets. We say $A$ is a subset of $B$ if$...$ every element of $A$ is an element of $B$ and there is an element of $B$ that is not an element of $A.$ every element of $B$ is an element of A and there is an element of A that is not an element of $B.$ every element of $A$ is an element of $B.$ every element of $A$ is an element of $B$ and every element of $B$ is an element of $A.$ every element of $B$ is an element of $A.$ there is an element of $B$ that is not an element of A and there is an element of A that is not an element of $B.$ None of the above Let A and $B$ be two sets. We say $A$ is a proper subset of $B$ if$...$ every element of $B$ is an element of A and there is an element of A that is not an element of $B.$ every element of $A$ is an element of $B$ and every element of $B$ is an element of $A.$ there is an element of $B$ that is not an element of A and there is an element of A that is not an element of $B.$ every element of $A$ is an element of $B$ and there is an element of $B$ that is not an element of $A.$ every element of $A$ is an element of $B.$ every element of $B$ is an element of $A.$ None of the above