Read the following passage from "Marriage is a Private Affair.
"The old man at once felt the resolution he had built up over so many years falling in. He was telling himself that he must not give in. He tried to steel his heart against all emotional appeals. It was a re-enactment of that other struggle. He leaned against a window and looked out. The sky was overcast with heavy black clouds and a high wind began to blow filling the air with dust and dry leaves. It was one of those rare occasions when even Nature takes a hand in a human fight. Very soon it began to rain, the first rain in the year. It came down in large sharp drops and was accompanied by the lightning and thunder which mark a change of season. Okeke was trying hard not to think of his two grandsons. But he knew he was now fighting a losing battle. He tried to hum a favourite hymn but the pattering of large rain drops on the roof broke up the tune. His mind immediately returned to the children. How could he shut his door against them? By a curious mental process he imagined them standing, sad and forsaken, under the harsh angry weather—shut out from his house.
That night he hardly slept...
According to the passage, what is the most likely reason that Okeke cannot sleep?
He regrets that he has acted so stubbornly and has caused his grandsons to suffer.
He is worried about the damage the storm will cause to his house and property.
He realizes that the season's change has come too early for his crops to grow well.
He is angry with his daughter-in-law for the emotional appeals to see his grandsons.