Final answer:
Option D). The model 1152 conductivity meter, with proper batteries, is approved for hazardous locations, as it is designed to prevent sparking or heating that could ignite flammable materials.
Step-by-step explanation:
The model 1152 conductivity meter is approved for use in hazardous areas as long as it is powered by the correct batteries. These kinds of devices are meant to keep people safe in situations where dust, vapors, or flammable gases could cause a fire. Like the model 1152, conductivity meters frequently have intrinsic safety features that stop them from creating heat or sparks in these hazardous environments that could cause an explosion.