Task: Please answer the multiple choice question.
Question: Which molecule has the longest half life time in humans after IV administration?
Constraint: Even if you are uncertain, you must pick either a or b without using any other words.
Options:
(a) O=P1(NCCCl)OCCCN1CCCl
(b) C[C@@H](O)[C@H]1C(=O)N2C(C(=O)O)=C(S[C@@H]3CN[C@H](C(=O)Nc4cccc(C(=O)O)c4)C3)[C@H](C)[C@H]12
Answer: a
Task: Please answer the multiple choice question.
Question: Which molecule has the longest {half_life_duration__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%half_life_duration%}
Answer: {%multiple_choice_result}
N,3-bis(2-chloroethyl)-2-oxo-1,3,2λ5-oxazaphosphinan-2-amine