1 in 7 appleS becomeS green? or, 1 in 7 apple becomeS green? or, 1 in 7 appleS become green? [duplicate]

Which of the following is proper grammar usage?

1 in 7 apples becomes green
1 in 7 apple becomes green
1 in 7 apples become green

One in seven apples becomes green.

("One in seven apples" means "one [apple] in seven apples"; the "apples" belongs to the "seven", but the verb agrees with the "one [apple]".)

Edited to add: Maybe there's a dialectal difference, or other point of disagreement? Edwin Ashworth links to a similar question whose answers, and their vote-counts, seem to suggest a division between those who agree with me and those would accept "One in seven apples become green." I'm still inclined to recommend becomes, because I know that some speakers accept only become and I do not know whether any accept only become, but that's a recommendation grounded in uncertainty. Hopefully someone can provide more useful evidence.