Auxin and Ethylene
Gibberellin and Cytokinin
Gibberellin and Abscisic acid
Cytokinin and Abscisic acid
Correct option is A. Auxin and Ethylene. Plant hormone auxin induces flowering in pineapple. Ethylene also helps in synchronization of flowering and fruit set up in pineapple. So, the correct answer is 'Auxin and Ethylene'