A volcanic eruption on the coast of Japan in 1850 deposits a layer of ash on top of a layer of red clay, and the ash is covered by a layer of silt in a tsunami in 1902. Archaeologists find a coin between the ash and silt, and they find a small pot between the ash and clay. Given this sequence of events, which of the following is true?

a. The pot is younger than the coin.
b. The pot is older than the coin.
c. The pot and the coin are the same age.
d. The coin is older than the pot