The original sentence has a misplaced modifier, which causes confusion about who or what is trying to keep their balance on the icy surface. In the original sentence, it suggests that "the last competitor" is trying to keep her balance, but it is more likely that it is the speaker (or someone else) who is trying to keep their balance.
Option A repeats the original sentence without making any changes, so it still contains the misplaced modifier.
Option B rephrases the sentence to clarify that it is the ski-tip of the last competitor that caught the pole and somersaulted, but it does not address the issue of the misplaced modifier.
Option C correctly rephrases the sentence to indicate that the last competitor caught the pole with the tip of her ski and somersaulted into the soft snow. It fixes the issue of the misplaced modifier and provides a clear and grammatically correct sentence.
Option D introduces a relative clause with the pronoun "which," but it is not necessary and makes the sentence more wordy.
Option E changes the sentence structure and focuses on the somersault rather than the action of catching the pole. It also introduces the passive voice, which can make the sentence less clear.
Therefore, option C is the best choice as it resolves the issue of the misplaced modifier and provides a clear and concise sentence.