Rick Rocker, a citizen and resident of country F, decides to perform a concert in Los Angeles. The U.S. promoter has agreed to pay Rocker $1 million. Rocker himself incurs $200,000 of expenses in connection with the concert. When the promoter pays Rocker his fee, the promoter:

(a) should withhold $300,000 of U.S. tax.

(b) does not have to withhold any U.S. tax.

(c) must withhold tax at Rockers marginal rates.

(d) should withhold $240,000 of U.S. tax.