Which of the following sentences uses commas correctly?

Summarize the article. be sure to cover the pros and cons of the four methods of waste management

How do i can change this sentence : a modern physician in a small town not only is proficient in general medicine but surgery as well. to parallel structure?

How can behavioral science be applied in improving public health? a. by tracking a disease to determine its sourceb. by creating promotions that improve health habitscboth by tracking a disease to determine its source and by creating promotions that improve health habitsd. neither by tracking a disease to determine its source or by creating promotions that improve health habits