किमो ऽत्

This debars त्रल् ॥ Thus किम् + अत् = क्व + अ 7.2.105 = क॑ as क्व भोक्ष्यसे 'where will you eat'. क्वाध्येष्यसे । According to some त्रल् also comes, as कुत्र ॥ This is done by drawing the word वा 'optionally' from the next sutra. So that this sutra becomes an optional one.,