The correct answer is A). They are rich in oil which promotes fire movement through the biome.
The chaparral biome has hot, dry summers, cool, moist winters with thin, nutrient poor soils. The vegetation includes both evergreen and deciduous forms. Plants in this biome are dominated by woody evergreen shrubs with small, leathery leaves. Herbs with fragrance and oil grow during winter and die in summer. Herbs contain flammable oils are always threat to fire.