Final answer:
The old Mariner in 'The Rime of the Ancient Mariner' stops the Wedding Guest, and not his companions, for reasons open to interpretation, including possible receptivity to the Mariner's story or a resonance with his own experiences.
Step-by-step explanation:
In Samuel Taylor Coleridge's The Rime of the Ancient Mariner, the reason the old Mariner stops one of the three wedding guests, as opposed to his companions, is subject to interpretation. The poem doesn't explicitly state why the Wedding Guest is chosen, but it may be suggested that the Mariner sees something in the Wedding Guest that signifies he is in need of hearing the Mariner's cautionary tale. Perhaps the Wedding Guest exhibits a disposition that resonates with the Mariner's experience, or he may simply be the most accessible or receptive to the lesson at hand. Moreover, the sudden and intense encounter that unfolds suggests a fateful meeting, one that underscores the poem's themes of fate, guilt, and redemption.