Option a ) the blanket was as white as snow is not an example of personification. This option is a figure of speech involving the comparison of one thing with another thing of a different kind. In this case, it is using both the blanket and the snow as a comparison. That is an example of a simile. So, that cannot be our answer.
Option b ) the alligator's teeth are white daggers is, again, not an example of personification. his option is a figure of speech involving the comparison of one thing with another thing of a different kind. In this case, both the alligator's teeth and the white daggers are being compared to one another. This is another example of a simile. So, this cannot be the answer.
Option c ) the star winked at me is an example of personification. This option gives something that is not human, human traits. In this case, the start posses human traits by it winking at a person. A star cannot wink. This is an example of personification. So, this is the correct answer.
Option d ) the fish swam across the river as if it was dancing is not an example of personification. Though it does almost sound as if the narrator is describing the fish to be dancing, the narrator is actually describing the movement of the fish which seems like it is dancing. When looking at a fish swim, a fish can be seen as if it is dancing because the fish is flowing with the water. But fish cannot dance. So, this cannot be the answer.