suppose you have the following four portfolios: portfolio a: a $100 face-value 2-year risk-free bond with 4% semi-annual coupons. coupons are paid on january 1 and july 1. portfolio b: a $100 stock with expected 3% annualized dividends paid quarterly. dividends are expected to be paid on january 1, april 1, july 1, and october 1. portfolio c: a $100 cryptocurrency etf with expected 4% annualized dividends paid quarterly. dividends are expected to be paid on january 1, april 1, july 1, and october 1. portfolio d: a $100 mortgage with two years remaining and 8 payments remaining. the interest is 3% annual interest. assume the interest is the same amount for each quarter (does not depend on the number of days). mortgage payments are quarterly.\