Answer:
C). Running is great exercise, and it is inexpensive. You can run on a treadmill, or you can run outdoors. You should not run on icy roads, however.
Step-by-step explanation:
As per the question, option C i.e. 'Running is great exercise, and it is inexpensive. You can run on a treadmill, or you can run outdoors. You should not run on icy roads, however' exemplifies the revision of the sentence that most effectively connects the ideas and variety. The correct use of transition words like 'and', 'or', 'however,' etc. appropriately establishes the transition between the ideas in a smooth and coherent manner. It helps maintain a flow in the ideas effectively. Thus, option C is the correct answer.