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Está nervioso
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a. practice makes perfect right?

b.i don't think that's a good choice

c.hmm..are you sure about that

d. that shows how immature that person really is

answer ..a

~hope this ~

corras is the only one that is informal but doesn't follow the suffix rule. correr is the verb. corre is the formal verb form. corra would be used as the formal is corre ended with an a.

your best bet would be corras, it's the only one that is informal but is still wrong