Based on Bloom's taxonomy the answer is knowledge. On the six levels, the question falls on level 1. The question tries to recall the name of the planets in the solar system which is knowledge based.
Knowledge questions require previous known facts and data. The common terms used in giving this type of question are; who, what, why, when, omit, where, which, choose, find, how, define, label, show, spell, list, match, name, relate, tell, recall, select (bloomstaxonomy.org). These key words are used to questions to identify the knowledge level of an examinee.
