Reporting and Tracking: Tracking Options

This answer partly depends on what publishing format you use and how your LMS is configured.

In many instances, a Storyline module is published to SCORM ("Shareable Content Object Reference Model") standards. SCORM defines a series of standard fields for the LMS, including one for "user completion of the online content" (my terminology and definition). Because there is a single field for that data, Storyline can only report a single data point for each user; thus, "[t]he first selected option the learner completes gets reported to the LMS/LRS."

There are other data that could be reported by Storyline, but publishing to SCORM limits that capability. So using some type of xAPI output, or configuring your LMS differently, could take advantage of the additional data. But for a great number of users, and their LMSs, it's practical to publish the course to SCORM standards and use a single data input to track completion or failure.