Answer :
Final answer:
Choose the closest lathe RPM setting of 260 RPM to the calculated 300 RPM as operating above the required RPM can cause damage or safety risks.
Explanation:
If you have calculated the RPM (Revolutions Per Minute) for a lathe operation to be 300 RPM and have to choose between the two available settings of 260 RPM and 350 RPM, you would typically select the setting that is closest to your calculated RPM without exceeding it. In this scenario, you would choose 260 RPM (a. 260 RPM). This is because operating at a higher RPM than required could cause damage to the tool or workpiece, and may also present safety risks. If precision is critical and neither setting is suitable, it might be necessary to adjust the lathe manually to reach the desired RPM. However, since 'adjust the lathe manually' is not given as an option, the most appropriate choice given the options would be 260 RPM.