Which of the following is a symptom of black-pod disease of cacao?

The correct answer is "small brown spot first appears on the pod". Black pod disease is a major fungal disease of cacao plants that causes damage to the pods and beans, leading to significant economic losses. The initial symptom of black pod disease is the appearance of small, water-soaked brown spots on the surface of the pods. These spots then enlarge and become sunken lesions, causing the pods to rot and turn black, hence the name "black pod disease." The disease can spread quickly and cause significant damage to the crop, leading to reduced yields and quality of cacao beans. Therefore, timely detection and management of the disease is essential for successful cacao production.