Final answer:
The correct answer to the question is 'ran'. This is because the sentence is in past tense and is referring to an event that has happened in the past, making 'ran' the appropriate form of the verb 'run' to use.
Step-by-step explanation:
In the sentence, 'While Jeffery was traveling in France, he _____ into an old friend from college,' the correct form of the verb 'run' to complete the sentence is 'ran'. The primary reason for this is that the sentence is in past tense and is referring to an event that has already happened. Here, Jeffery's action of running into an old friend is a completed action in the past, hence we use the simple past tense form of the verb, which is 'ran'. Options a) 'was running', b) 'has run', and d) 'runs' are incorrect grammatically in this context.
Learn more about Past tense