AIIMS 2018 Zoology Secondary Metabolites Assertion Reason Question

Option B is correct because the assertion that secondary metabolites of plants can be useful for humans is true; these compounds often have medicinal properties, such as alkaloids and flavonoids, which can be beneficial in pharmaceuticals. However, the reason provided, stating that abrin and ricin are toxins, does not explain the assertion, as these specific metabolites are harmful rather than useful. Option A is incorrect because the reason does not correctly explain the assertion. Option C is incorrect since the assertion is true, and the reason is also true but does not relate to the assertion. Option D is incorrect because the assertion is indeed true.