removeAttribute doubt from mock exam

[Bobby Sharma]

Here the question :

Given that scoped attribute cart exist only in user's session,which two
taken independently ,ensure that scoped attribute cart no longer exits?

A)<c:remove var="cart"/>
B)<c:remove var="${cart}"/>
C)<c:remove scope="session">cart</c:remove>
D)<c:remove scope="session" var="cart"/>
E)<c:remove scope="session">${cart}</c:remove>
According to mock exam's ,the answer is C and D.And it explains that
removeAttribute default is page scope.So B doest not work and incorrect.

I tested the code and found out the real answer should be B and D.
Because c give compilation error ,declaring that body content is empty.

please explain which answers are correct.

best regards,
omi

[Christophe Verré]

Definitely not C. Why did you choose B ? What about A ?

[Bobby Sharma]

sorry chris ,I chosen actually A and mistakenly typed B.

thanks for your reply.