The answer is A I believe
<span>The muscle at the end of the esophagus is not able to close, which allows stomach acid and digested food to go back up into the esophagus. </span>
There are many forms of electromagnetic energy<span> including gamma rays, x rays, ultraviolet </span>radiation<span>, visible light, infrared </span>radiation<span>, microwaves and radio waves. </span>
