According to the textbook:

• Statement A is correct: All Gibberellins (GAs) are acidic .
• Statement B is incorrect: Abscisic acid (ABA), not auxin, generally acts as an antagonist to Gibberellins (GAs) .
• Statement C is correct: The search for natural cytokinins led to the isolation of zeatin from corn-kernels and coconut milk .
• Statement D is correct: Ethylene induces flowering in mango .