Final answer:
The correct pair of verbs to fill in the blanks in the sentence is option C: a vecu, a rencontre.
Step-by-step explanation:
The correct pair of verbs to fill in the blanks in the sentence is option C: a vecu, a rencontre. This is because both of the verbs should be in the passé composé tense to indicate past actions. 'Ma mère a vécu en France' means 'My mother lived in France' and 'quand elle a rencontré mon père' means 'when she met my father'.
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