Hello!
The easiest way to see the possible choices is expressing them as chemical equations:
A) solid iron and chlorine gas react to produce solid iron (iii) chloride
Fe(s) + Cl₂(g) → FeCl₃(s)
B) solid iron and chlorine gas react to produce solid iron (iii) chlorate
Fe(s) + Cl₂(g) → Fe(ClO₃)₃(s)
C) aqueous iron and chlorine gas react to produce solid iron (iii) chlorate
Fe(aq) + Cl₂(g) → Fe(ClO₃)₃(s)
D) aqueous iron and chlorine gas react to produce aqueous iron (iii) chloride?
Fe(aq) + Cl₂(g) → Fe(Cl)₃(aq)
So, the correct answer is A
Have a nice day!