Select the option that expresses the given sentence in passive voice.

She blew the candles on the cake.

The candles on the cake were blown by her.

The correct passive form of the sentence She blew the candles on the cake is The candles on the cake were blown by her.

The active voice of the sentence is She blew the candles on the cake. This sentence is in the simple past tense, which is used to describe an action that happened in the past. The passive voice of the sentence is formed by putting the subject of the active sentence after the verb "to be" and the past participle of the main verb. In this case, the subject of the active sentence is "candles on the cake" and the main verb is "blow." The past participle of "blow" is "blown." So, the passive form of the sentence is The candles on the cake were blown by her.

The other options are incorrect because:

• The candles on the cake were blew by her. has a typo. The past participle of "blow" is "blown," not "blew."
• The candles on the cake was blown by her. is in the singular form, but the subject of the sentence is plural.
• The candles on the cake were being blown by her. is in the present progressive tense, which is used to describe an action that is happening now but is not finished. The sentence is describing an action that happened in the past, so the present progressive tense is not appropriate.
• The candles on the cake is blown by her. is in the present tense, but the action of the candles being blown happened in the past.