It is up to you to decide which alternative to choose based on which category best fits your intention to return to the U.S. and your voting state.
If you do not have a current intention to return and indicate “My return is uncertain”, you will receive a federal ballot (i.e., President and Congress) and more than half of the states (31) will send you a state ballot (i.e., governor, state legislature, etc.)
You may instead indicate “I intend to return” if you have an intention to return, even if you have no fixed return date or firm plans to do so. Every state will send a ballot for state offices as well as federal elections. But please also see FAQ #26 (“Are There State Income Tax Consequences If I Indicate On My Federal Post Card Application (FPCA) That “I Intend To Return”).