Use reasoning to answer the following question.
Where could you find a pebble that has been walked on?\nOptions:\n- lake\n- playground\n- pond\n- aquarium\n- stucco

playground
Playgrounds have small pebbles.

Kids walk and play on the pebbles in the playground.

One can find a find a pebble that has been walked on, in a playground.

.

The answer is playground