Final answer:
The correct verb to complete the sentence is 'a. me mantengo', which means 'I stay'.
Step-by-step explanation:
In this sentence, Luisa is talking about herself and how she stays in shape with volleyball training. The correct verb to complete the sentence is a. me mantengo, which means 'I stay'. This verb form matches the subject 'Luisa' and reflects the first-person singular form.
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