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:

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:

Option 1 : X = 24, Y = 12             True ribs are dorsally attached to vertebral column but are free on ventral side.

Option 2 : X = 24, Y = 7               True ribs are dorsally attached to vertebral column but are free on ventral side.

Option 3 : X = 12, Y = 5                True ribs are attached dorsally to vertebral column and sternum on the two ends.

Option 4 : X = 12, Y = 7                      True ribs are attached dorsally to vertebral column and ventrally to the sternum.