Final answer:
Ronald's minimum total reading time during a 120-day period, when reading at least one hour every day, would be 120 hours.
Step-by-step explanation:
Ronald's minimum total reading time for the 120-day period would be achieved if he reads for at least one hour on each of those days. Therefore, the calculation would simply be 1 hour/day × 120 days, which equals 120 hours.
So, the answer to the question is c) 120 hours. This assumes that Ronald reads for only one hour on each day and does not exceed this minimum time on any of the days.