Assertion : Amphioxus has a simple organization compared to vertebrates.
Reason : Many important craniate structure are lacking in Amphioxus.

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

A

Explanation

Amphioxus is devoid of heart, head, kidneys and paired limbs. Paired sense organs are absent here receptors are of primitive types. A complete notochord is persistent with no vertebral column. This shows that it has a simple organization compared to vertebrates because many important craniate structures are lacking in it. But it is definitely a simple chordate having a large number of primitive characters such as a notochord, dorsal hollow nerve cord, and gill clefts.