Final answer:
The subject of the sentence is 'My mother', who performs the action of cleaning the bathroom.
Step-by-step explanation:
The subject of the sentence is My mother. It is the person or thing performing the action of the verb in the sentence. In this case, the verb is 'cleans' and the subject is 'my mother'. The other options in the question, 'bathroom' and 'my', are not the subjects because they are not performing the action of the verb.
Learn more about Subject in a sentence