Yes but there’s an intermediate step. Also I don’t know what study book you have but it has excellent traps!!
CO2 can’t displace oxygen as is:
CO2 + H2O ---- H2CO3 (carbonic acid) ---- H⁺ + HCO3⁻ (hydrogen carbonate)
then H⁺ + HbO2 ---- H°Hb + O2
as you can see hydrogen ions displace O2 at the end of the reaction so 4) is correct
Carbon monoxide competitively binds to heme! it will kick out O2 and takes its place, which is why CO poisoning is so dangerous, so 2) is correct