The fact that historians have done harm by distorting truth, means that people believe what is reported by the historians. So, I is implicit. II does not follow from the statement and so is not implicit.
10. Statement: "As there is a great demand, every person seeking tickets of the programme will be given only five tickets."
Assumptions:
The organizers are not keen on selling the tickets.
No one is interested in getting more than five tickets.
Clearly, the organisers are adopting this policy not to reduce the sale but to cope up with great demand so that everyone can get the ticket. So, I is not implicit. Also, due to great demand, the maximum number of tickets one person can get has been reduced to five. So, II is also not implicit.