A Student Gave a Molecule the Following Name: 2-Ethyl-3-Methyl-5-Isopropylhexane

A student gave a molecule the following name: 2-ethyl-3-methyl-5-isopropylhexane
However, his TA pointed out that although the molecule could be correctly drawn from this name, the name violates the systematic rules. What is the correct (IUPAC) name for the molecule?

A) 3,4,6,7-tetramethyloctane
B) 3,4-dimethyl-6-isopropylheptane
C) 1,2-diethyl-3,6,7-trimethylheptane
D) 2,3,5,6-tetramethyloctane
E) 2-isopropyl-4,5-dimethylheptane