Ribs that are attached to the thoracic vertebrae and ventrally connected to the sternum with the help of hyaline cartilage are called

Read the following Assertion $(A)$ and Reason $(R)$ and choose the correct option.
Assertion $(A):$ All $12$ pairs of ribs are called bicephalic.
Reason $(R):$ Each rib is connected dorsally to the vertebral column by $2$ heads of articulation.

Atavistic epiphysis is a/an

Floating ribs of the thoracic cage are

In humans,out of $X$ pairs of ribs,only $Y$ pairs are true ribs. Select the option that correctly provides the values of $X$ and $Y$ and their explanation.

The number of bones in the adult human body is