Final answer:
The metal with a relatively low melting point used in fire detection and extinguishing devices and electrical fuses is aluminum (C).
Step-by-step explanation:
The metal that has a relatively low melting point and is used in fire detection and extinguishing devices as well as in electrical fuses is aluminum (C).
Aluminum has a melting point of 660.32 degrees Celsius, which is relatively low compared to other metals. It is widely used in various applications due to its lightweight, corrosion resistance, and good electrical conductivity.
Its low melting point makes it suitable for fire detection and extinguishing devices, as well as electrical fuses where it can melt to break the circuit and prevent damage.