Here's why:
* Length: It has 12 letters, which is a considerable length for a word ending in '-tion'.
* Common Usage: It's a relatively common word, making it a plausible answer.
It's important to note that:
* Technical terms: There might be obscure, technical, or scientific terms that are longer. However, those might not be commonly known or considered "true words" in everyday language.
* Compound words: There could be compound words ending in '-tion' that are technically longer, but they might be considered "constructed" rather than individual words.
Therefore, while there might be longer words out there, "ratification" is a good, widely recognized example of a long word ending in '-tion'.