typical industrial fan roller bearing with a rotational frequency of 1500 RPM shows an increase in peak-to-peak acceleration from 2 g's to 4 g's. What would the proper action be? A) Shut the machine down and replace the bearing. B) Schedule the machine for dynamic balancing at the next shut down. C) Inspect the base bolts for looseness. D) Analyze the stored spectrum and waveform to determine the exact cause of the increase and continue to monitor for further change