Final answer:
The correct action before interlocking ductile is to clean the ends of the pipes, removing any debris or contamination that could affect the connection quality.
Step-by-step explanation:
When preparing to interlock ductile pipes or components, it is important to take specific steps before making the connection. The most appropriate action to take before interlocking ductile is b) Clean the ends. This process involves removing any debris, dirt, or grease that could compromise the seal or connection. While the other options listed are relevant in different contexts, such as sanding the surfaces for certain types of connections that require a rougher surface for adhesion or applying lubricant to ease the joining process, cleaning is the fundamental first step. Additionally, it's important to check for cracks to ensure structural integrity. Not mentioned in the options but also critical is to always observe safety precautions and follow the manufacturer's instructions.