What is #K_2#...for #2CO(g) + O_2(g) rightleftharpoons 2CO_2(g)#?

Given....#2CO(g) + O_2(g) rightleftharpoons 2CO_2(g)#
....for which #K_1=6#...what is #K_2# for the reaction...
#2CO(g) + O_2(g) rightleftharpoons 2CO_2(g)#?:
#A.# #K_2=36#; #B.# #K_2=6#; #C.# #"unknown"#; #D.# #2.50#?