`{:(,"Column I",,"Column II"),((A),"An element with +1 stable oxidation state",(p),"lead"),((B),"A neutral oxide",(q),"Dry ice"),((C),"An element with stable +2 oxidation state",(r),"Thallium"),((D),"Solid carbon dioxide",(s),"Carbon monoxides"):}`
A. A-p,B-q,C-r,D-s
B. A-r,B-s,C-p,D-q
C. A-r,B-p,C-q,D-s
D. A-q,B-s,C-r,D-p
