Final answer:
The correct answer is c. Present perfect. This tense is used to describe an action that started in the past and is still relevant in the present.
Step-by-step explanation:
The correct answer is c. Present perfect.
The present perfect tense is used to describe an action that started in the past and is still relevant in the present. In this case, George repaired many cars in the past and has now received his mechanic's license. The use of the word 'before' indicates that this action took place before getting the license.
Example: George has repaired many cars before he received his mechanic's license. (Here, the action of repairing cars is connected to the present because George now has his license.)
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