DEF Enterprises acquired a patent for $80,000, paying $20,000 in cash and signing a note payable for the remaining balance. The note has a term of 3 years and an annual interest rate of 5%. Requirements: a. Determine the amount of note payable. b. Calculate the annual interest expense for the first year. c. Prepare the journal entry to record the acquisition of the patent. d. Determine the total interest expense for the first year.