Safe state does not guarantee a deadlock free system. Safe state means we have a sequence, which if followed will give us a deadlock free operation. But resources can be allocated in such a manner that the system may enter into deadlock.
Suppose you have $4$ processes ($P_1$,$P_2$,$P_3$,$P_4$) where $P_3$ and $P_4$ has no requirements now, but $P_1$ and $P_2$ needs $3$ and $4$ instance of resources respectively to finish execution.
Let’s say $P_3$ holds $2$ instances of resource at max and $P_4$ holds $3$ instances of resource max. Now, if both releases the resources we’ll get total of $5$ instances of resources. Now coming to Option A, it is saying that my system is deadlock free as max requirement is by $P_2$ which is $4$ and it is less than total free reources $5$.
But what if we allocate $2$ out of the $5$ resources to $P_3$ and remaining $3$ resources to $P_4$. $P_3$ and $P_4$ will both still need 1 resource but we have exhausted all resource. Hence system gets into deadlock.\
Even unsafe state does not guarantee deadlock. A process can pre-empt and release all its resources to make the state safe.
