The first answer is correct: "They suggest that the heat is stifling, giving the poem an oppressive mood".
The author begins the poem with the sentence cited above. The use of the expression "rend open" plus the use of the imperative mode, suggest some sort of desperation caused by the heat. That is why the author prays for wind (an unbeatable natural force) to come and defeat heat, ending the suffering.
2. I think is B
3. Is A
hope this helps.
