I contract to sell you Duke the goat for $50. When you come to pick up Duke, I tell you that I just can't part with him and it is impossible for me to go through with the contract. Group of answer choices a. My contract obligation to sell you Duke with be discharged because it is impossible for me to sell him to you. b. I must sell you Duke, or I will be liable to you for breaching the contract. My subjective "I can't do it" does not make it "impossible" for me to sell Duke and satisfy my obligations under the contract