which of the following statement(s) is/are correct about a medicare savings account (msa) plans? i. msas may have either a partial network, full network, or no network of providers. ii. msa plans cover part a and part b benefits but not part d prescription drug benefits. iii. an individual who is enrolled in an msa plan is responsible for a minimal deductible of $500 indexed for inflation. iv. non-network providers must accept the same amount that original medicare would pay them as payment in full.