Activity Series of Metals

Given below are the following four observations of four metals.
$1.$ Metals A and B slowly react with water.
$2.$ Metal C will displace metal B from its chloride salt solution.
$3.$ Metal D will not react with dilute acids.
$4.$. Metal C will not displace metal A from its sulphate salt solution.
Their reactivity order from the most to the least reactive is:

Which one of the following four metals would be displaced from the solution of its salts by other three metals?

Which of the following metals exist in their free state in nature?

(1) Gold                                (2) Copper

(3) Aluminium                        (4) Silver

The correct reducing ability order of the metals $\mathrm{Na}, \mathrm{Ag}, \mathrm{Ca}$ and $\mathrm{Sn}$ is