Out of 'X' pairs of ribs in humans only 'Y' pairs are true ribs. Select the option that correctly represents values of X and Y and provides their explanation

Options

A. `{:(X=12, Y=5,"True ribs are attached dorsally to"),(,,"vertebral column and sternum on two"),(,,"ends"):}`
B. `{:(X=24, Y=7,"True ribs are dorsally attached to"),(,,"vertebral column but are free on ventral"),(,,"side"):}`
C. `{:(X=24, Y=12,"True ribs are dorsally attached to"),(,,"vertebral column but are free on"),(,,"ventral side"):}`
D. `{:(X=12, Y=7,"True ribs are attached dorsally to"),(,,"vertebral column and ventrally to the"),(,,"sternum"):}`

Answer

D