Which of the Following Allows a Defendant to Be Held

Multiple Choice

Which of the following allows a defendant to be held liable for infringement even though the subject matter he used contained elements that were not identical to those described in the patentee's claims of invention,but nonetheless,may be seen as equivalent to those of the patented invention?

A) Literal infringement
B) Double jeopardy clause
C) Strict liability
D) Doctrine of equivalents