The correct option is
A Capitulum
A. Capitulum or head in which main axis becomes flat and called receptacle. It bears many sessile and small florets. Peripheral florets called ray florets are pistillate or neuter and zygomorphic, whereas disc florets are bisexual and actinomorphic. It is type of racemose inflorescence. A capitulum or head, the characteristic inflorescence of the sunflower family (Asteraceae).
B. Verticillaster is a cluster of sessile or subsessile flowers borne on a dichasial cyme ending in a monochasial cyme (scorpioid) in the form of condensed whorl on either side of the node. It is a type of cymose inflorescence. Examples are tulsi and salvia (Lamiaceae).
C. Cyathium looks like a single flower. A cup shaped involucre formed by bracts encloses a single female flower and a number of male flowers. Each male flower is represented by a single stamen, while a single pistil represents a female flower. It is a type of cymose inflorescence. The example is Poinsettia.
D. Hypanthodium is fleshy receptacle forming a hollow cavity with an apical opening called ostiole. The flowers are developed on the inner wall of the hollow cavity. The male flowers are situated at the top near the opening, at the bottom are situated the female flowers with long styles and in between both are situated short-styled gall flowers which are sterile. It is a type of cymose inflorescence. The example is banyan.
So, the correct answer is 'Capitulum'.