A system has 6 identical resources and $N$ processes competing for them. Each process can request atmost 2 requests. Which one of the following values of $N$ could lead to a deadlock?

1. 1
2. 2
3. 3
4. 4

My attempt :

Deadlock free condition is :

$R \geq P(N-1)+1 ,$

Where R is total number of resources ,

P is the number of processes , and

N is the max need of each resource .

$6 \geq P(2-1) + 1$
$6 \geq P + 1$
$5 \geq P$

So , number of processes should be less than $5$ for deadlock free condition.

Hence, all options can not be deadlock .

In this exercise problem answer given option (4).

What I'm missing here ?