Assertion: Urea is a less toxic excretory substance comparatively to urice acid.
Reason: Birds and insects are ureotelic animals.
A. Both Assertion and Reason are true and Reason is the correct explanation of the Assertion
B. Both Assertion and Reason are true, but Reason is not the cunect explanation of Assertlon
C. Assertion is true, but Reason is false
D. Both Assertion and Reason are false