On January $1,2020,$ Purple Inc. purchased a patent for $$33,300.$ Legal fees paid in this purchase amounted to $$1,700.$ The legal remaining life of the patent is $14$ years, but Purple believes it will only help increase sales for the next $10$ years.

On January $1,2023,$ Purple was sued for patent infringement and had to spend $$4,900$ of legal fees in the successful defense of this patent. What is the book value of this patent on December $31,2023?$

Select one:

a$.$ $$21,000$

b$.$ $$25,200$

c$.$ $$30,240x$

d$.$ $$19,600$

e$.$ $$24,500$