Which item is not helpful to Alex while travelling through a desert?
Option A: Umbrella is used to protect yourself from heat and rain.
Option B: Sweaters are used to keep the body warm in winter. But the desert has a hot climate. So, it is not helpful for Alex in this case.
Option C: Due to the hot climate of desert, our body needs more water to cool the body down. Alex should drink plenty of water. So, it is helpful.
Option D: Similar to umbrellas, caps are also helpful in a desert.
So, option B is the correct answer.