Final answer:
A child using a stick to reach a toy out of reach best exemplifies emerging means-end behavior as it shows the child's ability to plan and use tools to solve a problem and achieve a desired outcome.
Step-by-step explanation:
The example that BEST exemplifies emerging means-end behavior is c) A child using a stick to reach a toy out of reach. Means-end behavior is a cognitive process where an individual identifies a goal and finds the means to achieve it. This behavior is indicative of problem-solving skills and is a significant milestone in the cognitive development of young children.
In the case of a child using a stick to retrieve a toy, the child has recognized a problem (toy is out of reach), identified an objective (to obtain the toy), and devised a plan involving a tool (using a stick) to accomplish the goal. This clearly demonstrates the cognitive ability to plan and execute actions with a specific outcome in mind.
Other examples such as stacking blocks or organizing toys show different aspects of cognitive and motor development, but the direct engagement in problem-solving with a clear objective and the use of a tool or method to obtain a desired result is best exemplified in the use of the stick to retrieve the toy.