WASHINGTON (AP) — Having lost patience with China, the Trump administration is studying new steps to starve North Korea of cash for its nuclear program, including an option that would infuriate Beijing: sanctions on Chinese companies that help keep the North's economy afloat. The renewed look at "secondary sanctions" comes as Washington seeks a forceful response to North Korea's test this week of an intercontinental ballistic missile that could strike the United States. [...] a wide array of U.S.