Question $43$ of $100$

A backdoor or trapdoor in software is best described by which of the following?

A portion of computer code that allows anti$-$virus programs to scan files at the application layer

A buffer address through which one running program can pass information and instructions to anotl

A function embedded in a program that allows the programmer to quickly gain access at a later tim

An application program interface used by other applications to enter and update a program