<u>Answer:</u> The correct answer is Option A.
<u>Explanation:</u>
Mole ratio is defined as the ratio between the stoichiometric coefficients of the molecules present in the chemical reaction.
For the given balanced chemical equation:

By Stoichiometry of the reaction:
3 moles of iron metal reacts with 4 moles of water to produce 1 mole of iron oxide and 4 moles of hydrogen gas.
The mole ratio of 
Hence, the correct answer is Option A.
If we are talking about moles then the answer to that is 0.22
The answer should be A, flammability.
The isotopes of the same element would result in the same chemical properties, as the number of protons and electrons are not changed, meanwhile, the physical properties would be slightly different with each other because they have different numbers of electrons.
Out of the 4 options, only option A is a chemical property. Chemical properties are the properties of an element reacting with other substances that creates new substances at the end. While physical properties are the ones that does not produces new substances or any reactions. They are usually observable and measurable.
Therefore, since flammability is a chemical property, the answer is A.