The correct answer is: A. Only assumption I is implicit
The Principal instructed all the teachers to be careful in class because some students may disturb other students. This means that the Principal believes that some students may not be able to control themselves and may disturb other students. This implies that the teachers need to be careful and take steps to prevent this from happening.
Assumption I is that the teachers will handle the situation properly and they will point out the naughty students. This is a logical assumption, as the teachers are responsible for maintaining order in the classroom. If they see students disturbing other students, they should take steps to stop it.
Assumption II is that the students will welcome the decision of the Principal. This is not a logical assumption, as there is no reason to believe that all students will welcome the decision. Some students may be upset that they are being singled out, and they may not appreciate the Principal’s intervention.
Therefore, only assumption I is implicit in the statement.