The correct answer is - a. deciduous forests and grasslands.
The temperate biomes are located between the tropical biomes, and the polar biomes. In this biomes, the dominant ones are the the deciduous forests, and the temperate grasslands. In the temperate biomes there are some differences between the biomes, but there is one that is common, and that is that there is no sharp change of temperatures, but instead there's seasons in which the temperature and precipitation are gradually changing, and also the temperatures in general are more mild and less extreme than the tropical and polar biomes.