There are seven quintillion five quadrillion grains of sand on all the beaches of the world. The exact number is not known.
I think the insurance that they should purchase is: C. supplemental insurance
Dental insurance is not covered by Medicare, so both HMO and Point of service is out of the option.
I think supplemental insurance will be the best option because it is the type of insurance sold by private companies that specifically cover the policies that are not covered by normal Medicare.
I believe it is C) 250 million metric tons
although i may be wrong