They have the poor girl ............... the whole house twice a day.a.cleansb.cleanedc.cleand.to clean

To answer the question, we need to determine the correct form of the verb that should be used in the given sentence.

The sentence states, "They have the poor girl ............... the whole house twice a day."

To fill in the blank, we need to choose the correct form of the verb "clean."

Option a: cleans - This is the present tense form of the verb, but it does not match the tense of the sentence, which is in the past tense.

Option b: cleaned - This is the past tense form of the verb, which matches the tense of the sentence.

Option c: clean - This is the base form of the verb, but it does not match the tense of the sentence, which is in the past tense.

Option d: to clean - This is the infinitive form of the verb, but it does not fit grammatically in the sentence structure.

Therefore, the correct answer is option b: cleaned.