The revision of the passage that best connects ideas and adds variety is - Running is inexpensive, yet you can run on a treadmill. You can run outdoors, however, you should not run on icy roads.
Explanation:
The sentences given are short and simple. But when it comes to fusing the meaning and making it sound better, linking words are used. Here, using the words "yet" and "however" all the short sentences are joined to form one sentence which sounds well and offers the correct meaning at the same time. The flow of the sentence is better. There is less amount of jarring and stopping which helps it to connect ideas and add variety to the joined sentences.
