Question

____ last night? A) Have the plants been watered B) Did the plants water C) Were the plants watered
D) Are they watered

Answer 1

Answer:

Were the plants watered last night?

Explanation:

"Last night" depicts the past. This means the action of "watering of plants" is an action of the past. So we'll use "was/were" because it's an action of the past.

Hope this helps!

Answer 2

C) were the plants watered last night?