Answer: the correct answer is C. Impermanent
Explanation: an affix is a letter or group of letters, for example "'im-", "un-" or "-y", which is added to either the beginning or the end of a word to form a different word with a different meaning. For example, 'un-' is added to "kind" to form "unkind". When this affix is added at the beginning of a sentence it is called a "prefix" and when it is added at the end is is called a "suffix". In this case the use of the prefix "im" makes the correct word "impermanent", which means not permanent.