Answer: Option (D) is the correct answer.
Step-by-step explanation:
A balanced equation is defined as the equation which contains same number of atoms on both reactant and product side.
For example,

Number of atoms on reactant side are as follows.
P = 1
Cl = 5
H = 8
O = 4
Number of atoms on product side are as follows.
P = 1
Cl = 5
H = 8
O = 4
Since, there are same number of atoms on both reactant and product side. Hence, this equation is balanced.
Thus, we can conclude that out of the given options
, this chemical equation is balanced.