Answer:
The answer is C. The partial pressure of hydrogen will be unchanged.
Explanation:
⇒ 
Argon with electronic configuration 
(that is atomic number 18) is an inert gas making it unreactive and it's addition to the reaction has no effect on the partial pressure of either the reactant or production or the state of the system.
The partial pressure of hydrogen will remain unchanged on the addition of Argon.
I believe it is d, a microhabitat is a small area which differs somehow from the surrounding habitat. Its unique conditions may be home to unique species that may not be found in the larger region.
Total change in energy = Heat produced by system + work done on the system
= 228 - 55
= 173 kJ
Because this energy is released as heat, the reaction is exothermic.
2Na + 2H2O ——> 2 NaOH + H2
