ABA acts as antagonistic to

1. ethylene 2. cytokinin
3. gibberellic acid 4. IAA
(c) Gibberellic acid ABA is stress hormone as it induces seed dormancy in plants. Whereas, gibberellic acid breaks down seed dormancy and induces seed germination so, both act opposite to each other, the refer are antagonistic to each other.
Page 250, XI NCERT