You're right, Velma, whatever you said.
2 seconds sound clip from Scooby-Doo, Where Are You! - Hassle in the Castle (S1E3).
You can hear this line at 00:01:52.679 in the Blu-ray version of the episode.
Quote context
[...]
- You sure picked a spooky day to go boating, Freddy.
- Well, it didn't start out that way. What could have happened?
- You're right, Velma, whatever you said.
- I said, we're lost in a fog.
- No, Shaggy. Go back to sleep.
- Sleep, nothing. I'm fixing me a super Shaggy sandwich.
- Like, wow, my favorite: A double-triple-decker sardine and marshmallow-fudge sandwich.
- Open the mouth, between the gums. Look out, stomach. Here it comes.
[...]