Samples of four metals A, B, C and D were taken and added to a solution individually. The results obtained have been listed as follows. A can displace B from its solution B can displace D from its solution C can displace D from its solution C can displace A from its solution Which is the most reactive metal?

The reactivity series of metals determines which metal can displace another metal from its salt solution. A more reactive metal displaces a less reactive one from its solution. From the given conditions: A can displace B → A is more reactive than B. B can displace D → B is more reactive than D. C can displace D → C is more reactive than D. C can displace A → C is more reactive than A. Since C can displace A, and A can already displace B and D, it means C is the most reactive metal in the given set.