2f is included in 2a. It does not apply to US Citizens.
2f apply only to foreign persons and entities whose income maintains its character when passed through or distributed to its direct or indirect foreign owners or beneficiaries. It is generally treated as effectively
connected to a trade or business within the United States. See the instructions for your tax return.
if you are a nonresident alien, you should be filing form 1040-NR, which Turbotax doesn't do
