问题：
[单选题]What is the key difference between German and Japanese maglev trains? ( )
AThe German maglev trains use super-cooled, superconducting electromagnets.
BThe German maglev trains Transrapid trains are not equipped with an emergency
battery power supply.
CThe Japanese maglev trains use super-cooled, superconducting electromagnets.
DThe Japanese Transrapid trains are equipped with an emergency battery power supply.
