Final answer:
The NFL's chief medical officer would likely recommend hand washing as the most effective strategy for preventing COVID-19 spread, as it is highly effective against various contagious illnesses. Additionally, social distancing and mask wearing are essential measures supported by health experts.
Step-by-step explanation:
The NFL's chief medical officer has suggested that the league's "most effective strategy" in preventing the spread of coronavirus would align with the guidance provided by health experts that frequent hand washing is the single most important defense against the spread of contagious illnesses, including coronavirus. This is because microbes, which are tiny organisms only visible under a microscope, live on various surfaces and can be transferred to our hands. By touching our faces, we allow these microbes to enter our bodies, potentially leading to illness. Social distancing and mask wearing are also critical measures to help prevent the spread of the virus, as conflicting messages and poor adherence to these guidelines have been linked to spikes in cases and deaths in various outbreaks around the world.