In the context of combating desertification in arid zones, the term "drought-resistant" refers to the ability of trees to withstand or survive in dry conditions with minimal water availability. Planting drought-resistant trees is a strategic approach to address the challenges posed by desertification, as these trees can thrive and contribute to ecosystem stability even in regions prone to drought. Options A, B, and C also relate to the concept of dealing with drought, but "drought-resistant" specifically emphasizes the ability of the trees to resist or endure the effects of drought. Therefore, it is the most suitable option in the given sentence.