The organisms “Cicada, Froghopper and Pond skater” are:

Insects

Cicadas, froghoppers and pond skaters are all insects belonging to class Insecta. Cicadas and froghoppers are sap-feeding insects, while pond skaters are adapted to moving across the water surface. Option A is incorrect because they are not birds. Option B is incorrect because they are not aquatic vertebrate fish. Option D is incorrect because they are not reptiles. Hence, option C is correct.