Which of the following represents the most effective overlapping?

In $N_2$ molecule,the atoms are bonded by

$\pi$ bond is formed by:

$A$ molecule $(X)$ has $(i)$ four sigma bonds formed by the overlap of $sp^2$ and $s$ orbitals,(ii) one sigma bond formed by $sp^2$ and $sp^2$ orbitals,and (iii) one $\pi$ bond formed by $p_z$ and $p_z$ orbitals. Which of the following is $X$?

Determine the number of sigma $(\sigma)$ and pi $(\pi)$ bonds in the following molecules: $(i)$ Methane,$(ii)$ Ethane,$(iii)$ Ethene,$(iv)$ Ethyne.

Given below are two statements :
Statement $(I)$ : The oxidation state of an element in a particular compound is the charge acquired by its atom on the basis of electron gain enthalpy consideration from other atoms in the molecule.
Statement $(II)$ : $p\pi-p\pi$ bond formation is more prevalent in second period elements over other periods.
In the light of the above statements,choose the most appropriate answer from the options given below :