25.The mutant form of prions is the causative agent of Mad Cow Disease in human. The major difference between mutant prions and the normal prions is that: (A) the mutant prions have a large percentage of α-helix whereas the normal prions have more β-sheets (B) the normal prions have a large percentage of α-helix whereas the mutant prions have more β-sheets (C) both the mutant prions and the normal prions have more β-sheets (D) both the mutant prions and the normal prions have a large percentage of α-helix