This is an incomplete question, here is a complete question.
The Henry's law constant for oxygen dissolved in water is 4.34 × 10⁹ g/L.Pa at 25⁰C.If the partial pressure of oxygen in air is 0.2 atm, under atmospheric conditions, calculate the molar concentration of oxygen in air-saturated and oxygen saturated water.
Answer : The molar concentration of oxygen is, 
Explanation :
As we know that,

where,
= molar solubility of
= ?
= partial pressure of
= 0.2 atm = 1.97×10⁻⁶ Pa
= Henry's law constant = 4.34 × 10⁹ g/L.Pa
Now put all the given values in the above formula, we get:


Now we have to molar concentration of oxygen.
Molar concentration of oxygen = 
Therefore, the molar concentration of oxygen is, 
They all are correct , so with that being said anyone of them can be right
Most of the surface of the earth is covered with water and looks blue from space.
Hydrochloric acid + Sodium hydroxide =Sodium chloride +water
Close all network ports, filter those you can't block
Firewalls are used to filter network traffic and are available as standard system software on most operating systems. Limit the openings hackers have to your server.