CO_(g) + H₂ O_(g) → CO_2(g) + H_2(g)
Calculate the standard heat change of the reaction above, if the standard enthalpies of formation of CO_2(g), H₂O_(g) and CO_(g) and CO_(g) in KJ mol ^-1 are - 394 -242 and - 110 respectively.

• A.+ 262 KJ mol ^-1
• B.- 262 KJ mol ^-1
• C.+ 42 KJ mol ^-1
• D.- 42 KJ mol ^-1
• E.