A is not great, I would expect "as they have always done", but it is grammatically right. D is definitely wrong for 2 reasons.

1) what is the subject of "has been done"? what has been done? The author is referring to 'the harvesting of grapes' but that noun is not in the sentence. You will not find the -specific subject in the sentence

2) D is passive: "[something] has been done". In contrast, A is active: "they have done". Active is preferred to passive unless there is no active choice that is grammatically and meaning-wise correct.

A construct is passive if you can add "by the actor" after the action (the actor is the agent who performed the action). For instance, "harvesting has been done" is passive because we could say "harvesting has been done by the farmers"

-Patrick