The most appropriate unit to take the weight of a cow would be kilograms.
Meters are a unit of distance and are not applicable here
A gram is too small to use in this instance
It's a weak base bacause H C N is weak
SO₄²⁻ +NH₃ → SO₃²⁻ + H₂O +N₂
The balanced of the above redox reaction is as below
3SO₄²⁻ + 2NH₃ → 3SO₃²⁻ + 3 H₂O + N₂
Explanation
According to the law of mass conservation the number of atoms in the reactant side must be equal to number of atoms in product side.
Inserting coefficient 3 in front of SO₄² , 2 in front of NH₃, 3 in front of SO₃²⁻ and 3 in front of H₂O balance the equation above. This is because the number of atoms are equal in both side.
for example there are 2 atoms of N in both side of the reaction.
I think the answer is A but i'm not sure
The Answer is 10 it a little difficult to explain but I’ll try my best