The correct answer is 'easier'.Let's explore the given sentence:Here, in the sentence, the usage of 'than' required to be succeeded by a comparative adjective degree. Therefore, in the blank we require a comparative adjective degree.Comparative adjectives are formed either by adding œ-er to the end of the adjective, or by adding the word more (or less) before the adjective.Adjective that only have one syllable or two syllable and ends in '-y', we add '-er' to the end of the adjective.Example: Tall-Taller, Happy- HappierAdjectives that have two syllables and they do not end in '-y' or adjectives that have three or more syllables, we insert, more/less before these adjectives.Example: Careful- more/less careful, Intelligent- more/less intelligentTherefore, the required comparative adjective is 'easier'.Thus, the correct answer is: Getting to the top is easier than staying on top.Additional InformationComparative Adjective: Comparative adjectives are adjectives that compare differences between the attributes of two nouns. These are often measurements, such as height, weight, depth, distance, etc., but they dont have to be. We can also use comparative adjectives to compare non-physical characteristics.?Example: Sweet- sweeter