The correct option is C K>Na>Ca>Mg>Al>Zn
In the reactivity series of metals, metals are arranged based on their ability to react. As we move down the reactivity series , the tendency of metals to lose electron decreases. i.e, the metal in the top-most position of the reactivity series would readily lose an electron while the one at the bottom-most position would not.
So, the correct order of metals based on their tendency to lose eklectron is: K > Na >Ca > Mg > Al > Zn.