Jean Piaget observed children to see how they solved problems. Over the course of many studies, he was able to spot general patterns of behavior. This process led him to connect different concepts and behaviors within a single:
A. theory B. hypothesis C. experiment D. sample

   A. Theory

Explanation:  Before a scientist goes into research, he makes the best guess, which is a hypothesis to prove. Hypothesis are proved on a specific sample by conducting experiments and recording data and results from those experiments, which may or may not confirm the initial hypothesis, that is, the proof is correct or not. If the proof is correct, then this is the theory, that is, the collected data from the experiments conducted on the sample, and where the obtained data, ideas, concepts, complement each other, make this way the theory. So the theory obtained explains why an occurrence occurs according to a proven initial assumption.

Thus, Piaget also observed children's behaviour, that is, how children solve problems, collected data and proved the initial hypothesis, linking different concepts and behaviours into one theory.

the federal government of the united states was established by the constitution. us is a presidential republic. the president is head of state, head of government and of a two party legislative and electoral system. the supreme court balances the powers of the federal and the state government. yhe executive branch is headed by the oresident. there are two chambers of congress, the senate and the house of representatives. judicial power is exercised by the judicial branch (or judiciary), comprised of the supreme court and lower federal courts. the judiciary's function is to interpret the   constitution as well as the federal laws and regulations.