Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. optĭo, ōnis, f. [opto], choice, free choice, liberty to choose, privilege, option (class.): optio haec tua est, utram harum vis condicionem, accipe, Plaut. Cas. 2, 4, 13: nec mihi jus meum optinendi optio est, id. Cas. 2, 2, 19: utro frui malis, optio sit tua, Cic. Fat. 2, 3: vobis datur, utrum velitis, you have your choice, id. Caecin. 23, 64: potestatem optionemque facere alicui, ut eligat, to let a person have his choice, id. Div. in Caecil. 14, 45: eligendi cui patroni daretur optio, id. Brut. 50, 189: hiberna legionis eligendi optio delata commodum, id. Att. 4, 19, 2 (4, 18, 3): optionem tribuere, Sulp. Sev. p. 191 Horn.: optionem proponere, Ambros. Poenit. 2, 6, 50; Aug. Trin. 14, 19: trium tibi datur optio, Vulg. 2 Reg. 24, 12; id. 1 Par. 21, 10: tutoris, selection, Gai. Inst. 1, 150.
2. optĭo, ōnis, m. [opto], a helper whom one chooses for himself, an assistant (anteand post-class.).