It’s not “taking” classes, but matriculating to (enrolled in) a program leading to a degree. You can learn how UC sees it by looking through the UCOP web info. “A transfer applicant has been enrolled in a regular session at a college or university after high school.”
Also, UCOP calls DE and “concurrent” baiscally the same thing. And also that summer classes are an exception.
So, OP you can see you ned to go to the source.