SHANGHAI — Official data show Chinese vehicle sales were muted in March, rising 1 percent from a year earlier as carmakers cut prices to counter slack demand. The China Association of Automobile Manufacturers said Wednesday that 1.84 million vehicles were sold in March, up from 1.8 million a year earlier. Sales in the first quarter slipped nearly 4 percent, however, to 4.79 million vehicles. China, the world’s largest market for new vehicles, has seen sales growth slow over the past year, though sales for foreign automakers have fared relatively well. General Motors earlier reported its sales in China rose 8.7 percent in the first quarter, to a record 745,152 vehicles.