Final answer:
Rigor mortis generally sets in within 2 to 6 hours after death, not within the 10-30 minute timeframe. Answer choice d (ten hours) is closer to the average onset time, though it tends to begin earlier.
Step-by-step explanation:
Rigor mortis, which is the stiffening of the muscles after death, typically sets in within 2 to 6 hours post-mortem, reaching its maximum at around 12 hours, and gradually dissipates after 24-48 hours. Although the process can be influenced by several factors such as ambient temperature, the physical condition of the deceased, and the cause of death, the 10-30 minute range is too short for the beginning of rigor mortis. Considering a more realistic timeframe and the usual onset, ten hours (answer choice d) would be closer to the average time for rigor mortis to be noticeable but it commonly begins before this.