Thanatophoric dysplasia is a lethal skeletal dysplasia with distinct characteristics. Which type of Thanatophoric dysplasia is associated with a "cloverleaf" skull deformity, and what genetic mutation is usually responsible for this condition?

A) Type I; FGFR2 mutations
B) Type II; FGFR1 mutations
C) Type I; FGFR3 mutations
D) Type II; FGFR3 mutations