He smiled hugely , proud of himself for surprising Jack . He had n't liked lying to him on the phone , but he had been thinking for a week about surprising Jack and getting home a day early , and he had to admit that he was happy about being able to fool Jack and make him think he was coming on Thursday , when in reality he was flying in the day before , on Wednesday . What he had n't counted on was getting delayed in Chicago .
According to the above context, choose the best option to answer the following question.
Question: What may be the reason he was delayed in Chicago ?
Options:
- He forgot to write down his phone number .
 - The weather was too cold to fly safely .
 - None of the above choices .
 - The weather was too warm to defrost planes .


The weather was too cold to fly safely .