Official gauges of China’s factory and nonfactory activity plunged to record lows in February as the nation’s economy struggled to resume normal production as it faced the coronavirus epidemic. The official manufacturing purchasing managers index tumbled to 35.7 in February from 50 in January, indicating a deep contraction. February’s reading from the National Bureau of Statistics on Saturday was the first official data for a full month of economic activity in China since the coronavirus began affecting the economy…