How Does an Expression Vector Differ from a Regular Cloning

Multiple Choice

How does an expression vector differ from a regular cloning vector?

A) An expression vector does not have an origin of replication.
B) An expression vector is always a linear molecule, while a cloning vector may be circular.
C) An expression vector has the ability to have the inserted DNA be transcribed.
D) An expression vector must be of viral origin, so that it can infect a cell naturally.