The correct option is D was going / met
The first sentence indicates an action that continued in the past till a definite time, hence, past continuous tense (was/were+ verb+ing) should be used. The second sentence indicates an action that occured and ended in the past, hence, simple tense of the verb should be used, that is , "met". Hence, Option D is correct. The rest of the options do not adhere to this rule, hence incorrect.