Hello! Your answer is C, one atom of iron and three atoms of chlorine.
In this case, there is some ambiguity with "Cl". It could be C + I, or Cl. (One being carbon + iodine and the other Chlorine). However, we can see that the only choice that mentions iodine states two atoms, which is incorrect, as if it was iodine, the 3 indicates that there would be three atoms.
Therefore, Cl must be chlorine. If you look at choice C, there are three atoms of chlorine, as indicated by the 3 at the end of the Cl. There is also one molecule of Fe, as there is no number at the end of it so there has to be only one.
B is not correct, as carbon would be only "C". A is not correct as a molecule is a collection of atoms bonded together, therefore, this compound could be named a molecule, but there are not multiple molecules inside this compound.
Hope this helps!
