Task: Please answer the multiple choice question.
Question: Which molecule has the highest acute oral toxicity (LD50 in rats)?
Constraint: Even if you are not sure, you must pick either a, b, c, or d without using any additional words.
Options:
a. O=c1nc2[nH]c(=O)[nH]cc-2[nH]1
b. CCOC(=O)C(C(C)=O)C(=O)Cc1c(C)n(C(=O)c2ccc(Cl)cc2)c2ccc(OC)cc12
c. COc1cccc(C2(O)CCCCC2CN(C)C)c1
d. CCCn1c(=O)c2[nH]c(C)nc2n(CC(C)C)c1=O
Answer: b
Task: Please answer the multiple choice question.
Question: Which molecule has the highest {acute_toxicity__names__noun}?
Constraint: Even if you are {#uncertain|not sure!}, you must pick either {%multiple_choice_enum%2-5%aA1} without using any {#other|additional!} words.
Options:
{SMILES%acute_toxicity%}
Answer: {%multiple_choice_result}