Fill in the blanks with the most appropriate option:-

It ___________ raining when Ranu got home last night.

was

The most appropriate option to fill in the blanks is was.

The sentence "It was raining when Ranu got home last night" is in the past tense, and it is referring to a specific event that happened in the past. The other options are not as appropriate.

• Were is the past tense of the verb "to be" in the plural form. This does not make sense in the context of the sentence, as the speaker is talking about a single event that happened in the past.
• Has is the present perfect tense of the verb "to be". This does not make sense in the context of the sentence, as the speaker is talking about an event that happened in the past, not an action that started in the past and is still happening now.
• Being is the present participle of the verb "to be". This does not make sense in the context of the sentence, as the speaker is talking about an event that happened in the past, not an action that is happening now.