Read the following context and choose the best option to answer the question.
Context: I ' m impressed we managed to stick to the path . It was all worth it though - we got to the top of the mountain at about 6 am and watched the sunrise , which was really spectacular . It was also absolutely flipping freezing and I had n't brought enough layers . That was n't pleasant .
Question: Why did n't I bring enough layers with me to climb the mountain ?
Options: 
A. I did n't have enough money to buy more layers
B. I did n't think it would be that cold
C. None of the above choices .
D. I had forgotten to bring extra layers even though I knew it would be cold


B