What should be done prior to disassembling the M16A3/M4A1 for cleaning?

The correct answer is to ensure the weapon is unloaded before disassembling the M16A3/M4A1 for cleaning. This is a critical safety precaution that must be followed to prevent accidental discharge while handling the firearm. Ensuring that the weapon is unloaded includes removing any magazine, pulling back the charging handle to visually and physically check the chamber for any rounds, and then safely placing the weapon on safe. Adopting this procedure is essential for maintaining safety during maintenance or cleaning, as it protects both the individual handling the weapon and those nearby.

Making sure the weapon is unloaded also sets the stage for safe and effective disassembly, allowing the individual to focus on cleaning without the worry of mishaps. The other options do not contribute to the fundamental safety measures required before handling the firearm in this way.