Read the given statement and assumptions carefully. Assuming that the information given in the statement is true, even if it appears to be at variance with commonly known facts, decide which of the given assumptions logically follow(s) from the statement.

Statement:

During exams, invigilators are not supposed to use mobile phones in the examination hall.

Assumptions:

I. Mobile disturbs students during examination.

II. Keeping mobiles switched off helps to improve their vigilance.