Which best addresses a potential counterclaim?

certain types of cancers take twenty to thirty years to develop, and cell phone studies have only been monitoring this potential connection for ten years or less. on april 3, 1973, the first mobile telephone call was made by martin cooper, who is now referred to and known as “the father of the cell phone.”
the portability of cell phones increases personal safety by affording people an easier and faster way to call for in the event of a serious or life-threatening emergency.
according to the federal communications commission and the food and drug administration, cell phone use has not been linked to an increased risk of brain tumors.
the answer is a.