Which is the drought resistant crop?

Sweet potato is a drought-resistant crop.
Drought resistance or tolerance is a broader term applied to plant species with adaptive features that enable them to escape, avoid, or tolerate drought stress.
The prolific root system of sweet potato makes it a drought-tolerant crop, although supplementary irrigation is required at the time of planting for proper sprouting and establishment. Water stress reduces stem extension and internode diameter of sweet potato cultivars.