Answer: Option (d) is the correct answer.
Step-by-step explanation:
Metals are the substances that have more number of electrons. In order to attain stability, metals lose electrons and thus becomes positively charged.
A metal with less number of valence electrons will be more reactive because it will readily lose its valence electrons to become stable.
For example, atomic number of potassium is 19 with electronic distribution is 2, 8, 8, 1. Potassium is a group I element. So, to become stable it will lose its 1 extra electron readily.
Therefore, we can conclude that the most reactive metals on the periodic table are placed on to the far left.