For safety purposes, those are best stored in:
B. furnace
This is the option that aligns with safety considerations, as items that need to be stored for safety reasons are often best kept away from living areas and heat sources. However, if you're referring specifically to items that require storage for safety (and assuming they are non-flammable), then D. wardrobe could also be a valid choice for personal items.
Please provide more context or clarify the types of items you are referring to for a more tailored response.