(1) The energy difference between ground state and first excited state increases on descending the Group 17
(2) I$_2$ conducts electicity to a small extent due to its self ionization 3I$_2 \leftrightharpoons $ I$_3$$^+$ + I$_3^{\text{-}}$
(3) Conductivity of I$_2$ increases on increasing temperature
(4) The compounds C$_n$ F$_{2n+2}$ are known as perfluoro componds
$\begin{array}{1 1} (A) (2) and (3) \\ (B) Only (3) \\(C) Only (1) \\ (D) Only (4)\end{array}$
