A. He didn't take an umbrella whereas it was rainy.
B. He didn't take an umbrella, but it was rainy.
C. He didn't take an umbrella although it was rainy.
Would you please show me which of these could be correct?
A. He didn't take an umbrella whereas it was rainy.
B. He didn't take an umbrella, but it was rainy.
C. He didn't take an umbrella although it was rainy.
Would you please show me which of these could be correct?
(C) is the correct sentence.
Whereas is used to show a contrast like "I write with my right hand, whereas you write with your left hand."
(B) could also be correct, but it would have a different meaning. (C) implies that he knew it was rainy, but (B) could mean that he didn't know. Sentence B would make more sense that way if it were 2 sentences:
He didn't take an umbrella. BUT IT WAS RAINY. DUN DUN DUN
You use although to show that even though it was rainy, he still didn't bring an umbrella. He just doesn't care.
As a conjunction, although shows surprise, while whereas and but show a contrast.
Therefore, choice c is correct.