Final answer:
Medicare Part A does not automatically cover a 70-year-old who is not eligible for Social Security option (b) benefits; while it primarily insures those 65 and older, coverage may extend to younger individuals with certain conditions or disabilities.
Step-by-step explanation:
The hospital expense coverage under Medicare Part A is not automatically available to a 70-year-old who is not eligible for Social Security benefits. Medicare Part A is designed to cover hospital charges for individuals who are eligible for Social Security benefits and is funded through payroll deductions.
Although Medicare primarily provides health insurance for those 65 and older, certain individuals under 65, such as those with disabilities or those with permanent kidney failure, may also be eligible. A 70-year-old not eligible for Social Security does not automatically qualify for Part A coverage and may need to buy into it.