Answer:
Im confused what are you talking about?
Answer:
B.) Who
Explanation:
The curator of the art museum, who gave a speech last night, will be attending tonight's ceremonies, as well.
The term "that" is a less formal way to put it. And using the term "which" does not make grammatical sense, so your best choice would be "who".
I would write them all out but im lazy. change the noun after the word by and make that the subject of the sentence followed by the verb and the rest of the sentence :)
1.The rooms are cleaned by Mary every day.
2.An article is written every day.
3.The window is cleaned already.
4.When i arrived somebody is cleaned the room.