The correct option is B 4 o'clock rainfall
Convectional rainfall is common in the hot and wet tropical rain forests of central Africa, Amazon basin of South America and the islands of south-east Asia. In the late afternoon, the clouds burst into a heavy downpour, often accompanied by thunder and lighting. It usually occurs at about 4 pm, so convectional rain is called 'four o'clock rain' and occurs daily in the equatorial regions.