they are prepare they document. buat ke kalimat passive bantu saya yahhh

the document is prepared by them

soalnya:
a) They prepare the document. atau
b) They are preparing the document.

jika a maka jawabannya sudah dijawab diatas.

jika b maka bentuk passivenya
(present continous)
Subject + tobe + being + Verb3

The document is being prepared by them.