The correct answer is C. Cities that have added bike lanes reduce bicycle fatalities by 45%.
Step-by-step explanation:
In writing, an argument refers to the main point or claim you try to prove through reasons and evidence, due to this, each element including reasons need to be directly connected to the argument and explain or prove it. In the case of writing an essay about the importance of adding more bike lanes a relevant reason would be "Cities that have added bike lanes reduce bicycle fatalities by 45%." because this shows the positive impact of adding bike lanes and therefore support the idea of "more bike lanes need to be added".