The correct answer is B. During drought, stomata can be closed to prevent excessive water loss through the process of transpiration.
Stomata are tiny pores or openings which are in plant tissue and they allow exchange of gas. They are found in the leaves of a plant.
Guard cells helps in the opening and closing of stomata. The pores allows in, carbon dioxide into the plant which is well known as needed during the process of photosynthesis.
They help in reducing water loss and that is why the leaves close when it is dry or hot. The closing and opening of stomata helps in the process of transpiration.
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