The correct answer to the question is semiconductor .
EXPLANATION:
Before coming into any conclusion, first we have to understand the nature of conductor, insulator and semi conductor.
A conductor is a type of material which has high conductivity and low resistivity. The free electron concentration in its conduction band is more as compared to insulator and semi conductor. As it has low resistance, it will provide low resistive path to the flow of electrons.
Insulator is the type of substance which has high resistivity. The free electron concentration in its conduction band is almost empty. Hence, it will provide high resistance to the current flow.
Semiconductor is the type of conducting substance whose resistivity lies between conductor and insulator. Its conductivity is less than conductor but greater than insulator. At room temperature, it behaves just like an insulator; but at normal room temperature, some of its valence electrons jump into conduction band and becomes free. Hence, it opposes the flow of electrons partially.
As per the options given in the question, the correct answer to the question will be semi-conductor.
