A parallel plate capacitor of capacitance C$0$ has plates of area A with a separation d between them. When it is connected to a battery of voltage V$0,$ the plates become charged with the charge $$Q$0.$ The capacitor is then disconnected from the battery and the space between the plates is filled with a material of dielectric constant $2.$ After the dielectric is added, the magnitudes of the capacitance, the potential difference between the plates, and the charge are

$($a$).$ C$0/2,2$V$0,2$Q$0$

$($b$).$ C$0,$ V$0/2,$ Q$0$

$($c$).$ C$0,$ V$0,$ Q$0$

$($d$).2$C$0,$ V$0/2,$ Q$0$

$($e$).2$C$0,2$V$0,$ Q$0/2$