Unlike the traditional multiple-choice (MC) format, the discrete-option multiple-choice (DOMC) format does not necessarily reveal all answer options to an examinee. The purpose of this study was to determine whether the reduced exposure of item content affects test security. We conducted an experiment in which participants were allowed to view study guides prior to taking a test comprised of DOMC and MC items. Results showed that the DOMC format seems to offer a slight advantage over the MC format in the presence of item preknowledge.