GMAT Sentence Correction (SC) | Re: The learning process often requires

a, the repetition of a specific action again and again until itis

'repetition' and 'again' convey the same meaning, thus it is redundant.

b, specific actions until theyare

this choice changes meaning by crossing out 'repetition'

c, the repetition of a specific action until that action hasbeen

Looks good to me but I don't think present perfect is needed

d, the repetition of a specific action until it is

Though 'it' seems ambiguous, pronoun ambiguity is not an absolute rule in SC. Thus, it
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