B . Behind them : impaired means to have a disability of a specific kind so being behind them you watch them
A cost-Benefit analysis (CBA) is the process used to measure the benefits of a decision or taking action minus the cost associated with taking the action. A CBA involves measurable financial metrics such as revenue eared or costs saved as a result of the decision to pursue a project.
Hope this helps
Answer:
The answer is B! Hope this helps
