Final answer:
The correctly punctuated sentence is option C: "The Olympic Games begin in three weeks; however, several venues aren't complete." The semicolon is used to separate two independent clauses, and the comma is used after "however" to indicate a contrast.
Step-by-step explanation:
The correctly punctuated sentence is option C: "The Olympic Games begin in three weeks; however, several venues aren't complete."
Option A is incorrect because it has an extra semicolon before the word "however." Option B is incorrect because it has unnecessary commas before and after the word "however."
In option C, the semicolon is used to separate two independent clauses, and the comma is used after "however" to indicate a contrast. This is the correct punctuation for this sentence.
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