The line "The sun used to smile in my hut" is an example of personification.
Personification is a figure of speech where human qualities or characteristics are given to non-human objects or ideas. In this line, the sun is being described as smiling, which is a human quality.
The other options - - Apostrophe: Apostrophe is a figure of speech in which someone absent, dead, or non-human is addressed as if they were present and able to reply. This is not the case in the given line, as the sun is not being directly addressed. - Rhetorical Question: A rhetorical question is a question asked for effect or to make a point, rather than to get an answer. The given line is not a question, so it does not fit this category. - Zeugma: Zeugma is a figure of speech in which a word is used in two different ways in the same sentence. The given line does not have such usage.
Therefore, the correct answer is personification.