Nelson (grantor) sells his home to randall (grantee)"subject to" an existing first mortgage loan he obtained five years ago. after nine months, randall can no longer continue to make the monthly payments. under these circumstances
a, the seller is primarily liable and the purchaser is secondary liable
b, the purchaser is primarily liable to the lender and the seller is secondarily liable
c, the purchaser is solely liable to the lender
d, the purchaser grantee has no liability to the lender