A and B are the compounds of carbon. A on passing over red hot coke is converted to B. Then A and B are respectively :

Question

$\begin {array} {1 1} (1)\;CO,CO_2 & \quad (2)\;CO_2,CO \\ (3)\;CH_4,C_2H_6 & \quad (4)\;CCI_4,CHCI_3 \end {array}$