To monitor the response time of emergency response teams to calls from the local community, a 3-sigma control chart for range is constructed. Samples of 4 response times are used. Their ranges are calculated. After 10 such samples are collected the average range is 4.1 minutes.

The upper and lower control limits for the range chart are

which one is correct?

8.33 and 1.5 minutes

9.35 and 0 minutes

10.1 and 3.3 minutes

7.3 and 0 minutes