What does the boy see on the walls of the cave?

The boy sees pictures on the walls of the cave, which typically suggests the presence of illustrations or representations that tell a story or depict scenes from life, experiences, or imagined scenarios. Such imagery can be deeply significant in conveying emotions, cultural narratives, or historical events. In the context of the cave, pictures often serve a symbolic or educational purpose, providing insight into the life or beliefs of the cave's inhabitants or creators. This choice aligns well with the idea of the cave often being a location for artistic expression or storytelling.

The other options, while related to forms of visual representation, do not capture the essence of what pictures often represent in literary and artistic contexts, particularly in caves where storytelling and the transmission of knowledge through visual means are emphasized. Carvings could refer to three-dimensional features, statues indicate more defined and substantial figures, and graffiti implies a more modern form of expression that lacks the historical significance typically associated with cave art.