Hint: This inflorescence can only be found in monocot plants, including fleshy axis and coloured bracts (spathes). This is commonly seen among Araceace, Musaceace, and Palmaceace members.
> Option A is incorrect. The inflorescence of catkins is a pendulous spike in the axis of the leaf that carries sessile and unisex flowers. It's sort of an inflorescence of racemose. One can see this sort of inflorescence in Mulberry, Betula, Oak.
> Option B is correct. The spadix is a spike that has a fleshy axis and flowers both male and female. It is surrounded by large bracts of color called a spathe. It's also kind of an inflorescence of racemose. The peduncle is fleshy, long, and dense. The flowers are small, sessile, and unisexual. For e.g., Colocasia, Maize, Aroids, Palms, Bananas, etc.
> Option C is incorrect. The compound umbel is branched and known as "umbel of umbels," and bear flowers of branches. This (umbel) inflorescence is characteristic of the family Apiaceae (Umbelliferae). It can be seen in coriander, fennel, carrot, etc.
> Option D is incorrect. A racemose inflorescence is a form in which the flowers branch on the floral axis laterally, the shooting axis continues to develop indefinitely, and the flowers are borne in an acropetal order (i.e., the lower or outer flowers are older than the upper or inner ones). Neem, Gulmohar (Delonix regia), is an example of the Racemose inflorescence.
Hence, The correct answer is option (B).
Note: Inflorescences are complex and have several roles. At anthesis, they present the flowers in ways that allow pollen transfer and maximizing the reproductive success of the plant. They provide nutrients to the growing flowers and fruits during the production of flora and fruit.