What citizenship should I choose for college

I am planning to apply to UC Berkeley. So I want to know that which citizenship has better opportunity for accepted, Korean or US citizen.

I’m not familiar with the UC application, but for other applications, it’s really not a choice - you list them all. But to answer the question, a US citizen will always (or at least 99.9999% of the time) have a better chance than an international applicant at a US college when all other things are equal (which is never the case).

This is from the UC application directions:

**Citizenship:
• Undocumented applicants have the option to choose “No selection” from the dropdown menu. This is option is a valid response, and we recommend this choice
for undocumented applicants, including those with Deferred Action for Childhood Arrivals (DACA) status.

• If students select a country other than the United States or “No selection”, they will need to provide their legal immigration status and the type of visa (e.g., F-1, H4, etc.) they hold or plan to hold upon enrollment.**

What is more important than Citizenship is State Residency since that will determine if you pay in-state tuition rates or out of state tuition rates.

Your citizenship won’t affect admissions. If there is a choice, go with USA simply because there are fewer questions that need to be answered.

Actually, citizenship affects admissions, always to the detriment of internationals. Since it won’t need a visa, though, you are a 'domestic applicant/us citizen and permanent resident and will have to report that you’re a US citizen, which is to your benefit anyway. (If there’s a question about any dual citizenship, you can add Korean to that specific question).
Will you graduate from a CA high school?

Absolutely US if you are applying to a School in this country. You can bring up the fact that you have dual citizenship in your application but for admissions, Fin aid and scholarship purposes, bring an American citizen is advantageous.