NEW YORK (AP) — Most U.S. stocks rose, but the worst drop for UnitedHealth Group in a quarter of a century kept Wall Street in check. The S&P 500 edged up 0.1% Thursday even as three-quarters of the stocks within the index climbed. Another drop for Nvidia helped pull the Nasdaq composite down 0.1%. The Dow Jones Industrial Average slumped 1.3%. That was almost entirely because UnitedHealth Group plunged 22.4% to its worst loss since 1998 after a weaker-than-expected profit report. Treasury yields rose following mixed data on the U.S. economy. President Donald Trump again criticized the Federal Reserve for…