Twelve-Year-Old Allen Argues That, "If Shamus Is a Man, and All

Twelve-year-old Allen argues that, "If Shamus is a man, and all men are mortal, then Shamus is mortal." Based on the information given in this statement, which of the following is most likely to be true about Allen?

A) Allen is in the concrete operational stage of development of Piaget's theory of cognitive development.
B) Allen can perform mental operations-on real, or concrete, objects and events-but still has trouble with abstract ideas and reasoning.
C) In this stage, Allen's logic remains concrete and limited to objects that he directly observes.
D) Allen is in the formal operational stage of Piaget's theory of cognitive development.