Final answer:
The preferred target areas for ECD deployment are the lower center mass for front shots and below the neck area for back shots to balance effectiveness and safety.
Step-by-step explanation:
The preferred target areas for Electronic Control Device (ECD) deployment are a) Lower center mass (below chest) and legs for front shots and b) Below the neck area for back shots. This guidance is aimed to be both effective and to minimize the risk of serious injury. It is advised against aiming ECDs at certain sensitive parts of the body, such as the head or face, due to the higher risk of injury.