Final answer:
Telling students to stop what they're doing immediately and get their coats for recess is not an effective transition strategy.
Step-by-step explanation:
Out of the given options, the transition strategy that is NOT effective is telling students to stop what they're doing immediately and get their coats for recess (option C). This strategy can be abrupt and may disrupt the flow of the class. It's important to give students a clear and gradual transition to the next activity to maintain a positive and organized learning environment.
Learn more about Transition strategies for class activities