AIIMS 2019 Zoology Acraniata Assertion Reason Question

Option B is correct because the assertion accurately describes Acraniata as organisms lacking a distinct cranium, while the reason correctly identifies that this group includes small marine forms without a head. However, the reason does not serve as a direct explanation for the assertion, as the absence of a cranium does not inherently imply the absence of a head in all contexts.

Option A is incorrect because, although both statements are true, the reason does not explain the assertion. Option C is incorrect since the assertion is true and the reason is also true, making it impossible for the reason to be false. Option D is incorrect because both the assertion and reason are indeed true.