Alternation of generation is absent in which coelentrate?

Explanation

Option C is correct since hydra only exhibits asexual reproduction by budding. As there is no sexually reproductive stage, alternation of generation is not possible. Alternation of a generation refers to the production of asexual form by sexual form and vice versa.Option A is incorrect since Obelia belongs to the class Hydrozoa in which both polypoid and medusoid forms show alternation of generation.Option B is incorrect since Jellyfish belongs to the class Scyphozoa and also consist of both sexual and asexual forms.Option D is incorrect since Sea Anemone also exhibits alternation of generation.