What Is the Simplest Definition of a Genetic "Logic Gate

Multiple Choice

What is the simplest definition of a genetic "logic gate"?

A) a promoter (which interacts with input signals such as regulatory proteins) and a gene, which produces mRNA and protein (output signal)
B) migration of negatively charged DNA in an electrophoresis experiment depends on molecular weight
C) energy-dependent transporters in the nuclear envelope
D) all of the above
E) none of the above