In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.

Question: Graphite is a conductor because:
Options: <1> The valence band has electronic vacancies. <2> The driving band has electronic vacancies. <3> Both bands have electronic vacancies. <4> The banned band is very big. <5> The band gap is zero.
5