The "medical loss ratio" legislated in the ACA is: A. An insurer's requirement that enough of the premiums collected are put into reserves to cover 2/3 of actuarial projected claims volume B. A regulation that allows insurance companies to write off losses due to extraordinary care expenses C. An insurer's requirement that a minimum amount of collected revenues pays for medical care of patients D. A percentage of premium dollars spent that allows insurers to apply for reinsurance