Which of the following types of orbital overlapping results in the formation of a $\pi$ bond?

The strongest bond is formed when atomic orbitals undergo:

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Zero orbital overlap is an out-of-phase overlap.
Reason $R$: It results due to different orientation/direction of approach of orbitals.
In the light of the above statements,choose the correct answer from the options given below.

Which of the following is correct for the $N_2$ triple bond?

Assuming the bond direction is along the $z$-axis,which of the following overlaps of atomic orbitals of two atoms $(A)$ and $(B)$ will result in bonding?
$I$. $s$-orbital of $A$ and $p_x$-orbital of $B$
$II$. $s$-orbital of $A$ and $p_z$-orbital of $B$
$III$. $p_y$-orbital of $A$ and $p_z$-orbital of $B$
$IV$. $s$-orbital of both $(A)$ and $(B)$

Which of the following would result in the formation of the strongest $\pi-$ bond if the molecular axis is the $x-$axis?