Final answer:
The traditional material used for the head of a tympani is calf skin, which delivers a rich and resonant tone. Modern tympani heads may use plastic, but traditionally, animal hide was the standard.
Step-by-step explanation:
The traditional material used to make the head of a tympani is A. Calf skin. Historically, calf skin was used because it provides a rich, resonant tone that is desirable in orchestral and ensemble settings.
Plastic is widely used in modern times due to its consistency and durability, but historically, animal hide was the preferred material. Metal and wood are not used for the heads of tympani but are materials commonly found in other aspects of drum construction, such as the shell and hardware.