Farmer Donald bought a $1.70 strike put option for $0.11 and sold a $1.75 strike call option for a premium of $0.14. His total costs are $1.65 per bushel and the continuously compounded risk-free interest rate is 7.84% over this period. What is the floor in his strategy assuming a 20,000-bushel crop?

a) $624

b) $1,624

c) $2,624

d) $3,624