At high $P{O}_2$ levels, where is most oxygen located?

$C{O}_2$ dissociates from carbamino haemoglobin when

(a) $pC{O}_2$ is high and $p{O}_2$ is low

(b) $p{O}_2$ is high and $pC{O}_2$ is low

(c) $pC{O}_2$ and $p{O}_2$ are equal

(d) None of the above