Task: Please answer the multiple choice question.
Question: Which molecule has the highest acute oral toxicity rat LD50?
Constraint: Even if you are uncertain, you must pick either a or b without using any other words.
Options:
a: Nc1cccc(-n2ccccc2=O)c1
b: CCCC(C)C1(CC)C(=O)NC(=O)NC1=O
Answer: a
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}