The sentence says: "They ran so fast that they ...'' meaning their speed led them to a result.
Step 1: Analyze options
- (A) "May have won'' is uncertain and does not fit well with the definite tone of the sentence.
- (B) "Won the race'' is simple past tense, clearly stating the outcome of their fast running.
- (C) "Winning the race'' is a present participle phrase and does not fit grammatically.
- (D) "Had won the race'' is past perfect tense, which is used for an action completed before another past action; unnecessary here.
Step 2: Choose best option
Option (B) is the most straightforward and grammatically correct choice.
Conclusion
Correct answer is (B).