Correct answer is
.
Phosphoric acid is a polyprotic acid having 3 acidic hyrdogen therefore it will have 3 pka values.
The equations for the release of acidic hydrogen can be written as:

From the pka values we can judge the idea of pH as using Henderson-Hasselbalch Equation, we get the relation between pH and pka.

Using the following equation, relation of pH and pka is
![pH=pka+log\frac{[A^-]}{HA}](https://tex.z-dn.net/?f=pH%3Dpka%2Blog%5Cfrac%7B%5BA%5E-%5D%7D%7BHA%7D)
Using this equation, we can find that the equation having pka= 2. 14 is closest to the pH=3.2 so the ionic form in this equation will be dominant at the same pH.
Therefore at pH=3.2 the ionic form
of
is dominant.
For the first two
1. Will only give up one atom to be stable
2. Only 2 atoms
<h2>Answer:</h2>
The option B is correct option. Which is release of heat and/or light energy .
<h3>Explanation:</h3>
According to the definition of exothermic reaction :
<em>An exothermic reaction is a chemical reaction that releases energy by light or heat.</em>
From definition option B (release of heat and/or light energy) indicates that an exothermic reaction has taken place.
.