WASHINGTON (AP) — U.S. inflation declined last month as the cost of gas, airline fares, and hotel rooms fell, a sign that price growth was cooling even as President Donald Trump ramped up his tariff threats. Consumer prices rose just 2.4% in March from a year earlier, the Labor Department said Thursday, down from 2.8% in February. That is the lowest inflation figure since September. Excluding the volatile food and energy categories, core prices rose 2.8% compared with a year ago, down from 3.1% in February. That is the smallest increase in core prices in nearly four years. Economists closely...