Correct Answer: A. Climate is largely responsible for determining the distribution of terrestrial biomes and is primarily determined by the mean temperature and precipitation in a region. For example, deserts and rain forests have similar mean temperatures but vary greatly in the amount of precipitation each receives. Although elevation is one factor that influences mean temperature (B), it does not solely contribute as much to biome distribution as mean temperature and precipitation do. Biomes can have distinct soil types (C). However, soil type is in part determined by the climate in a region, which is in turn determined by temperature and precipitation. Neither elevation nor soil type (D) have as much influence on biome distribution as mean temperature and precipitation do.
