Casey Is Four Years Old

Casey is four years old.She presents with a phonemic inventory of 5 consonants and 5 vowels,and inconsistent substitution,omission and distortion errors involving these speech sounds.The frequency of her speech sound errors increase as word length increases.She also exhibits monopitch and monoloudness.Her likely diagnosis is

A) Apraxia of speech
B) Spastic dysarthria
C) Hyopkinethic dysarthria
D) Mixed dysarthria