Final answer:
The expansion of a hollow viscus due to N₂O likely occurs rapidly, within minutes, but exact times are not provided in the reference information. In similar contexts, response times may be around 10-15 minutes but can vary.
Step-by-step explanation:
The question pertains to the time it takes for nitrous oxide (N₂O) to cause expansion of a hollow viscus. While the exact options for the expansion time of N₂O are not provided in the question itself, based on the context provided in the reference information, we can infer that the expansion caused by N₂O in biological systems is likely to occur more rapidly than the times listed in the options given for the water question. However, for educational purposes, a response time of 10-15 minutes could be suggested for an observable physiological change, although in practice, this could be slightly longer (20-30 minutes), as biological processes can vary.