Answer:
The colon should be placed after the word "Competitor". Therefore as already mentioned, THE ANSWER IS C. COMPETITOR .
Step-by-step explanation:
A colon is used between two independent clauses when the second part of the sentence expands,paraphrases or illustrates the first part.
So, White has one advantage over the newer, younger competitor: experience.
Here experience illustrated the first part of the sentence. So, competitor is the right option.
Hope it help!