The condition $num\ !=\ 65$ cannot be replaced by-

The condition is:

$num\ !=\ 65$

It means $num$ is not equal to $65$.

Option (a):

$num>65\ ||\ num<65$

This is true when $num$ is not equal to $65$.

Option (b):

$!(num==65)$

This also means $num$ is not equal to $65$.

Option (c):

$num-65$

In C language, any non-zero value is treated as true.

So, this is also true when $num\neq 65$.

Option (d):

$!(num-65)$

This becomes true when $num-65=0$, that is $num=65$.

So, it is opposite of $num\ !=\ 65$.