Cyathium and Hypanthodium type of inflorescence are similar in having:

Cyathium looks like a single flower. A cup-shape involucre is formed by bracts enclosing a single female flower and a number of male flowers. Each male flower is has single stamen while a single pistil represents a female flower. Eg; Euphorbia. 

Hypanthodium is fleshy receptacle to form a hollow cavity with an apical opening called ostiole. The flowers are developed on inner walls of the hollow cavity. The male flowers are present at the top near the opening & at the bottom are the female flowers with long styles and in between both are situated short-styled gall flowers which are usually sterile. Eg; Ficus.

The correct option is (D).