In Lecture, the Professor Named a Molecule 2-Ethyl-4-Tertiary-Butylpentane

In lecture, the professor named a molecule 2-ethyl-4-tertiary-butylpentane. An alert student pointed out that although the correct structure could be drawn from this name, the name did not follow systematic rules. What is the correct systematic name for the molecule?

A) 2-t-butyl-5-methylhexane
B) 2-ethyl-4,5,5-trimethylhexane
C) 3,5,6,6-tetramethylheptane
D) 2,2,3,5-tetramethylheptane
E) undecane