The reactants based on the reactivity capable of forming the products are . Thus, option A is correct.
The reactivity series has been the arrangement of the elements based on their reactivity. The highly reactive element has been capable of replacing the less reactive element in the compound, and form the product.
In the following reactions, the new product has been formed by:
From the reactivity series, Br has been more reactive than I, and thereby replaces iodine in the compound for the formation of product.
The compound has been formed with F. Cl has been less reactive than F, and will not be able to form the product.
The compound has been formed with Cl. Br has been less reactive than Cl, thus will not displaces Cl for the formation of new product.
The compound has been formed with F. I has been less reactive than F, and will not be able to form the product.
The reactants that will be able to form the products have been . Thus, option A is correct.
For more information about the reactivity series, refer to the link: