Which of the following will decrease the present value of the mixed cash flows for years 1 through 5 of $1,000; $4,000; $9,000; $5,000; and $2,000 respectively given a 10% discount rate? (Choose all that apply - this is an all or nothing problem; if you choose an option that is wrong or do not choose an option that is correct, your entire answer will be marked wrong).

a. Decrease the discount rate by 2%.

b. Switch cash flows for years 1 and 5 so that year 1 is $2,000 and year 5 is $1,000.

c. Switch cash flows for years 3 and 4 so that year 3 is $5,000 and year 4 is $9,000.

d. Switch cash flows for years 2 and 5 so that year 2 is $2,000 and year 5 is $4,000.

e. Switch cash flows for years 3 and 1 so that year 1 is $9,000 and year 3 is $1,000.

please explain, thanks!