-The passage tells us that stuttering………

A)is passed down genetically from fathers to sons

B)usually stems from the sufferer experiencing a sudden shock

***C)is a type of speech problem that affects a large number of people

D)can be avoided by neglecting to say the Initial sounds of words

E)is an incurable disease, and sufferers have no hope of recovery

A)know that stuttering is genetic, but haven't found the gene that causes it

B)doing research into stuttering generally agree with public opinion

***C)have not yet been able to determine exactly what causes stuttering

D)have discovered that both genetics and psychology cause stuttering

E)feel that stuttering is caused by emotional problems but can't prove this