Seven-Year-Old Xavier Is Given the Following Pair of Statements: "All

Seven-year-old Xavier is given the following pair of statements: "All of the balls in the tub are either red or blue. My ball is also in the tub." When asked, "What color is my ball?" he is able to answer correctly, "red or blue." A Piagetian researcher would say that Xavier is

A) incapable of abstract thinking.
B) capable of propositional thinking.
C) incapable of formal operational thinking.
D) capable of hypothetical-deductive reasoning.
E) capable of metacognition.