In which of these would the reaction rate be the quickest

There is no explanation/details given about the question. How we are supposed to answer then?

The beginning of a reaction is the fastest

Explanation: The concentration of the reactants is higher at the beginning of the reaction and thus resulting more successful collisions between the reactant particles which pushes the reaction to proceed in forward direction. The more successful collisions, the faster the reaction will be.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6