I believe your answer is B.
Answer:
0.1M NH3
Explanation:
The boiling point of aqueous solutions depend on the nature of intermolecular interactions present. KBr will yield an ionic solution but NH3 will yield a molecular solution having hydrogen bonds. The degree of hydrogen bonding in the aqueous solution will further increase with the concentration of the solution.
Remember that experimental data shows that hydrogen bonds are strong bonds that lead to a significant increase in the boiling point of solutions. Hence 0.1M NH3 solution will have a higher boiling point due to intermolecular hydrogen bonding in the solution.

1 mole of nitric acid produce 1 mole of ammonium nitrate.
moles in 5000 kg of ammonium nitrate :
( molecular mass of ammonium nitrate is 80 gm/mol )
So, number of moles of nitric acid required are also 62500 moles.
Mass of 62500 moles of nitric acid :

Hence, this is the required solution.
Answer:
The answer is 17.03052. We assume you are converting between grams Ammonia and mole.
I would maybe say solid at higher temps