A student asks if

AsubeB

and

BsubeC

, do we know

AsubeC

? How do you answer?\ Choose the correst response.\ A. There could be an element in

A

that is in

B

but not in

C

. Therefore, if

AsubeB

and

BsubeC

, it is not necessarily true that

AsubeC

.\ B. The expression

AsubeB

means every element of

A

is contained in

B

. The expression

BsubeC

means that every element in

B

is contained in

C

. Therefore, every element of

A

is contained in

C

, and so

AsubeC

must be true.

A student asks if AB and BC, do we know AC ? How do you answer? Choose the correst response. A. There could be an element in A that is in B but not in C. Therefore, if AB and BC, it is not necessarily true that AC. B. The expression AB means every element of A is contained in B. The expression BC means that every element in B is contained in C. Therefore, every element of A is contained in C, and so AC must be true