Answer: Option (a) is the correct answer.
Explanation:
Based on reactivity series, the reactivity of some metals in decreasing order is as follows.
Li, K, Ba, Ca, Mg, Al, Mn, Zn, Cr, Fe, Co, Ni
Thus, it can be seen that Al is more reactive than Fe, so it will replace iron in a single displacement reaction. Whereas cobalt is less reactive than iron hence, it will not replace Fe.
Fluorine being an anion will not replace a cation because in displacement reactions, only a cation can replace another cation and an anion can replace another anion.
Hence, we can conclude that Al will replace iron (Fe) in a compound during a single replacement reaction.
