The housewife __________ the cakes were burning and hurried to turn off the oven.

Explanation

The correct answer is 'smelt' (option C), which is the past tense of 'smell' used here to indicate that the housewife noticed the burning cakes before acting. Options A and B are present tense forms, D is a present participle, and E, although past tense, is less commonly used in British English.