The correct answer is option 'B' - Capsule or berry.

Explanation:
The Solanaceae family, also known as the nightshade family, includes many economically important plants such as tomatoes, potatoes, peppers, and eggplants. These plants produce fruits that are classified as capsules or berries.

1. Capsule:
A capsule is a dry, dehiscent fruit that splits open to release the seeds. In the case of Solanaceae plants, the fruit is typically a multi-chambered capsule that contains numerous seeds. The fruit wall of the capsule is tough and dry, and it opens along specific lines or pores when mature. Examples of Solanaceae fruits that are capsules include the fruits of the tomato (Solanum lycopersicum) and the chili pepper (Capsicum annuum).

2. Berry:
A berry is a fleshy fruit that develops from a single ovary and contains one or more seeds. In Solanaceae plants, the berry is a common type of fruit. It is typically juicy and has a soft pericarp (fruit wall). Examples of Solanaceae fruits that are berries include the fruits of the tomato (Solanum lycopersicum), the eggplant (Solanum melongena), and the bell pepper (Capsicum annuum).

Other options mentioned in the question:
a) Drupe: A drupe is a type of fruit that has a fleshy outer part (exocarp) and a hard inner part (endocarp) surrounding a single seed. The Solanaceae family does not typically produce drupe fruits.

c) Siliqua: A siliqua is a type of fruit that develops from a single carpel and splits open along two sides to release the seeds. This type of fruit is commonly found in the Brassicaceae family and is not characteristic of Solanaceae plants.

d) Achene: An achene is a small, dry fruit with a single seed that does not split open. It is typically attached to a larger structure (receptacle) by a stalk called a funiculus. While some plants in the Solanaceae family may produce achenes as part of their reproductive cycle, it is not the typical fruit type for this family.

In conclusion, fruits in members of the Solanaceae family are primarily capsules or berries.