Which of the following structures have the correct common name?

Question

Quizplus · Accepted Answer

-I is incorrect as it is a cyclohexane with a tert-butyl group (not a methyl group as in the common name)
-II is correct as it is a cyclohexane with an isopropyl group in the 1-position, which is commonly referred to as isopropylcyclohexane
-III is correct as it is a cyclohexane with a tert-butyl group in the 1-position, which is commonly referred to as tert-butylcyclohexane
-IV is incorrect as it is a cyclohexane with an ethyl group (not a methyl group as in the common name) in the 1-position.

Which of the Following Structures Have the Correct Common Name