An investment set up as a perpetual trust provides an annual disbursement of $$25,000$ for the first $20$ years and an undetermined amount from year $21.$ If the trust is set up with $$500,000,$ determine the disbursement that can be made from year $21$ through infinity if the interest earned is $6\%$ per year.

a$)$ $$41,031$

b$)$ $$54,000$

c$)$ $$60,090$

d$)$ $$58,500$