The correct statement is:
The earthquake was caused by plates moving together. It released a lot of energy, but the observer did not see much damage.
In this case, the earthquake at a convergent boundary indicates that the tectonic plates are moving together, which typically results in high-magnitude earthquakes that release a lot of energy. The low intensity reported by the observer suggests that despite the earthquake's high magnitude, the effects were not severe in their location, possibly due to factors like depth of focus, distance from the epicenter, or local geological conditions.