Assertion : Both true ribs and floating ribs are present in mammals
Reason : By nature, stenal ribs are true ribs as, they possess all the characters of ribs.

Options

A. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C. If the assertion is true but the reason is false
D. If both the assertion and reason are false

Answer

B

Explanation

All the sternal parts of the thoracic ribs except the last five, attached the sternum below by hyaline cartilage. Therefore, they are called as true ribs. Actually last two pairs of ribs (11th and 12th pair) provided with the sternal parts and they are not connected with the sternum and hence, known as floating ribs. Floating ribs protect the kidney.