What is the scientific name of Chilli?
A) Solanum melongena
B) Atropa acuminata
C) Capsicum annuum
D) Physalis peruviana

Hint:Chilli belongs to the family Solanaceae, the same family Green pepper belongs to.

Complete answer:
1) Solanum melongena is the botanical name of Eggplant or Brinjal. The edible fruit of Solanum melongena L., belongs to the genus Solanum. Solanum is one of the largest genera, having more than 1500 described plants. The other known names are melongen, garden egg, and guinea squash.
2) Atropa acuminata is a herbaceous perennial plant producing a branched stem from a tuberous rootstock; it can grow up to 160cm tall. The plant is toxic in nature but the plant has long been used in herbal medicine, the various alkaloids found in it is used by many pharmaceutical firms. The whole plant, and especially the root, is extremely poisonous. Symptoms formed once eaten include fever, rapid pulse, dilation of pupils, hot and dry flushed skin, headache.
3) Capsicum annuum includes bell pepper and chilly. It is a short-lived, evergreen perennial plant that is usually grown as an annual. It varies in height according to variety, but is generally about 1 metre tall.This species is widely grown throughout the world, but especially in warm temperate to tropical climates, for its edible fruit chilli peppers as a spice. It also has various medicinal properties.
4) Physalis peruviana, commonly known as Goldenberry, is a perennial plant that is harvested from the wild for local use as a food and medicine. The plant can grow up to 1.20 metres tall. All parts of the plant, except the fruit (which is edible in nature), are poisonous.
As seen above, the botanical name of Chilli is Capsicum annuum.

Thus, the correct answer is option C (Capsicum annuum).

Note:The genus for both Chilly and Bell pepper is Capsicum and their species comes under Capsicum annuum group.