According to Wambaugh's AOS Dx, if any feature from category D is present, the probability of AOS is which?

• A. High probability
• B. Moderate probability
• C. Low probability
• D. No AOS

Answer: (D)

The key idea is that in Wambaugh's AOS Dx, category D features are strong disqualifiers for apraxia of speech. If any feature from this category is present, it indicates a pattern that is not consistent with AOS, so the likelihood of AOS drops to zero. In other words, the presence of category D signs points away from apraxia and toward another motor speech mechanism, making “no AOS” the best choice. The other probability levels would only apply if category D features were not present, but once any category D feature shows up, the diagnosis of AOS is effectively ruled out.