Sales of previously occupied U.S. homes fell in March to their slowest pace nine months, as easing mortgage rates failed to motivate home shoppers during what’s traditionally been the busiest time of the year for the housing market. Existing home sales fell 3.6% last month from February to a seasonally adjusted annual rate of 3.98 million units, the National Association of Realtors said Monday. Sales also fell 1% compared with March last year, weighed down by declines in the Northeast and