The sentence that is best as it is is option B: Only Dave will go with us; the others are busy. The rest of the sentences contain incorrect parts such as the proper use of the word "only". In the first sentence, it should be "only to watch". In the third sentence, it should be "only drinks water". In the third sentence, it should be "Only Leah studied".
The term is self-contradictory.
The clergy is represented by the Prioress (and her nun and three priests), the Monk, the Friar, and the Parson. The other characters, from the wealthy Franklin to the poor Plowman, are the members of the laity