Answer:
3. Cellular phones have transformed telecommunication.
1. Before cell phones, people relied almost completely on land lines for business and personal communication.
2. Now, people can check the stock market or call home while waiting in line at the market.
4. Who knows, in the future, land line telephones may disappear altogether.
Step-by-step explanation:
This is the most logical order for these sentences. Sentence 3 should be the opening sentence because it is the one that introduces the main topic of the paragraph. Sentence 1 follows, because it introduces the background information. Sentence 2 develops from this background and introduces the description of how things are now. Finally, sentence 4 provides a prediction and concludes the paragraph.