If the app builder tries to convert a preexisting long text area field to text area, preexisting information will truncate to the first 255 characters. This means that any information beyond 255 characters will be lost. Option B is incorrect because preexisting information will not remain if it was over 255 characters. Option C is incorrect because preexisting information will not cause an error message to pop up. Option D is incorrect because preexisting information in the field will not be completely lost, only truncated.