What component provides the electrical power needed to operate the FMU-139/B fuze?

The FMU-139/B fuze requires a reliable power source for its operation, specifically to activate its electronic components and ensure that it functions correctly when required. The FZU-48/B initiator is designed to provide the necessary electrical power for the FMU-139/B. It incorporates an electrical energy source that, upon receiving the appropriate signals, activates the fuze’s mechanisms, allowing it to perform its critical roles during munition deployment.

In contrast, the other options serve different functions. The FZU-47/B initiator and FZU-49/B battery are not specifically tailored to power the FMU-139/B; instead, they have distinct roles in ammunition systems. The FZU-46/B charger, while related to power management, is primarily used for charging batteries and does not directly provide operational power to the FMU-139/B fuze. Thus, the FZU-48/B initiator stands out as the correct answer, given its direct involvement in powering the FMU-139/B fuze.