The correct option is B The oppressive weather due to high temperatures and high humidity in the month of October.
During the retreating monsoon season, temperatures are high during the day and nights are cool. Owing to heavy rainfall between the months of June and September, the land is still moist and hence the atmosphere is humid. Due to the hot temperatures and high humidity, the weather is oppressive. As this is primarily seen in the month of October, it is called October Heat.