Which of the following statements about plant growth regulators (PGRs) is incorrect?

Kinetin (a modified adenine, specifically N6-furfurylaminopurine) was discovered as a substance that promoted cell division from autoclaved herring sperm DNA, but 'kinin' as a general term was later replaced by cytokinin. Cytokinins were first isolated from unripe maize grains (zeatin). Wait, let's verify option C: kinetin was indeed isolated from autoclaved herring sperm DNA, but it is not a natural plant hormone (it is a synthetic/artifactual cytokinin). The statement C says 'Kinin was isolated...', however kinetin is the specific compound. Let's check another option if needed, but wait: kinetin was discovered by Miller et al. from autoclaved herring sperm DNA. Let's look closer: Kinetin does not naturally occur in plants. Therefore, stating kinetin was isolated from herring sperm is correct, but let's re-verify all statements to find the incorrect one. Auxin isolated from coleoptile tips (F.W. Went) - correct. Gibberellins from bakanae disease (E. Kurosawa) - correct. ABA purified as inhibitor-B, abscisin II, dormin - correct. Let's check if there's any subtle error. Actually, kinetin is a cytokinin derivative, but wait, 'Kinetin' was isolated from herring sperm DNA. Wait, is there a more blatant error? Let's check another question to be safe, or craft one with a clear fact.