Which of the following describes a flower with free petals and three series?

The technical term used for the androecium in a flower of China rose $(Hibiscus \text{ } rosa \text{ } sinensis)$ is

In the flowers of a plant,the ovarian part is fused,but styles and stigmas are free. Its ovary becomes unilocular due to breakdown of partition wall and the ovules are attached to a central axis. Identify the plant.

The keel is a characteristic feature of the flowers of .....

Placentation,in which ovules develop on the inner wall of the ovary or in the peripheral part,is:

Identify the type of petals in the given diagrams $(A, B$ and $C)$.