Answer:
A. Less than 2.9
Explanation:
Richter scale is a measure of the intensity of the earthquakes designed and developed by Charles Richter in 1935. Its value ranges from 1.0 to 9.0 and greater. The earthquakes having a Richter magnitude of less than 2.9 are minor earthquakes which are slightly felt by a few humans but can be recorded on a seismograph. Earthquakes with magnitude above 2.9 can easily be felt by humans.
