Which cognitive ability becomes evident during the formal operations stage?

During the formal operations stage, which typically emerges in adolescence according to Piaget's theory of cognitive development, individuals begin to engage in complex thinking that involves reasoning about abstract concepts and ideas. The correct option reflects the emergence of metacognition, or "thinking about thinking." This ability allows adolescents not only to understand their own thought processes but also to evaluate and regulate them, enabling more sophisticated problem-solving strategies.

Metacognition encompasses skills such as self-reflection, self-evaluation, and the ability to plan how to approach tasks. This skill is fundamental during adolescence as it allows for greater independence in learning and more effective decision-making as individuals begin to think more critically and systematically.

The other options relate to different cognitive abilities or stages. The use of trial and error is characteristic of earlier stages, particularly the concrete operational stage, where children rely more on physical manipulation and exploration. Reliance on tangible objects for understanding is also typical of preoperational and concrete operational thinkers, who tend to focus on physical, concrete experiences rather than abstract reasoning. Increased egocentrism is a trait associated with earlier developmental stages in childhood, where children are centered on their own perspective and find it challenging to see things from others' viewpoints.