Quote "It's asking me to select the lowest available flight level which complies with the quadrantal rule. The track is 063 so it's an odd flight level; the corresponding available options are FL30 and FL50. QNH is 1015."
The question asks for the lowest available flight level. Some basics - the transition altitude outside CAS is 3,000ft. The first fl30 on that track is FL30 and it is also the transiton level. The transition level is not available for use as it does not garauntee any separation from aircraft flying at the transition altitude. Therefore in this case FL50 is the first available FL on that track that provides any separation from the transition altitude.
