Calculate the present value of each cashflow using a discount rate of 7%. Which do you most prefer most?

Show and explain all supporting calculations!

Cashflow A: receive $60 today and then receive $60 in four years.

Cashflow B: receive $12 every year, forever, starting today.

Cashflow C: pay $50 every year for five years, with the first payment being next year, and then subsequently receive $30 every year for 20 years.

Cashflow D: receive $9 every other year, forever, with the first payment being next year.