Context: Later, during the Koine Greek period, the aspirated and voiceless stops /tʰ d/ of Attic Greek lenited to voiceless and voiced fricatives, yielding /θ ð/ in Medieval and Modern Greek.

Question: Attic Greek lenited to what?
Answer: voiceless and voiced fricatives

Question: The lenited Attic Greek yielded /θ ð/ in what periods?
Answer: Medieval and Modern Greek

Question: Arctic Greek yielded what other versions of the Greek language?
Answer: Unanswerable

Question: During what period did unaspirated and voiceless stops lenited to voiceless and voiced fricatives?
Answer: Unanswerable

Question: What represents unaspirated and voiceless stops?
Answer: Unanswerable

Question: Arctic Greek lenited to what?
Answer: Unanswerable