When referring to knowing where to find something when you need it you mean that you do not need a memorization of all things, you just need a source to find it when in need. I hope this answer suited your needs.
The correct option is C.
if two organisms are in the same class then they will be in the same phylum. The biological classification hierarchy is arranged in such a way that, two organisms who belong to a lower division on the hierarchy will automatically be in the same group in the higher division.
The arrangement from the smallest to largest hierarchy is this: specie, genus, family, order, class, phylum and kingdom.
