Human-created climate change is caused by A. decreased burning of fossil fuels.

B. increased carbon dioxide in the air.

C. increased oxygen in the air.

D. increased use of green energy sources.

B

hope that helps<3

B

Explanation: increased burning of fossil fuels coupled with deforestation have resulted in increased levels of CO2 in the atmosphere.

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.

your answer would be a, maximum exploitation of resources.