In the Final Formal Operational Stage of Piaget's Theory of Cognitive

In the final formal operational stage of Piaget's theory of cognitive development,

A) children can understand and articulate speech and symbols but can't understand common concepts such as weight
B) children are capable of abstract thought and reasoning
C) children understand causal relationships and concepts but can't reach conclusions through general principles
D) children can understand only what they can see, hear, and touch