Enigma to Solution Analogy

In the following analogy, examine the relationship between the words in the first pair and select a word that maintains a similar relationship to the word 'enigma' as the word 'solution' does to 'problem'.

An 'enigma' is a puzzling situation or subject, often requiring insight to resolve. Meanwhile, a 'solution' is what you find after addressing or solving a 'problem'.

Determine which word matches this relationship.