The correct answer is: Only assumption I is implicit.
The statement “If I am not well you will have to go for the meeting” implies that the manager is not the only person who can attend the meeting. If the manager was the only person who could attend the meeting, then there would be no need for him to make this statement. The statement also implies that the manager would prefer to go to the meeting himself if he was well. However, this does not necessarily mean that he would not want his subordinate to go to the meeting if he was not well.
Assumption I is implicit because the statement implies that the manager is not the only person who can attend the meeting. Assumption II is not implicit because the statement does not say anything about whether or not the manager would want to go to the meeting if he was well.