Choose the option that best expresses the meaning of the italicized part of the sentence:
Harish ran the marathon race in less than two hours.
The highlighted word, in this context, means 'finished'.
Option C is correct. 'Completed' means 'finished'. Thus, it has the required meaning and thus, it is correct.
Options A, B and D are incorrect. They do not have the required meaning.
'succeeded' means 'achieved', 'rushed' means 'travel fast' and 'scored' means 'gain points'.