Which could you date with carbon-c-14​

C-14 can be used for dating fossils (50,000-70,000 years)

Explanation:

A fossil is a preserved remains of a once-living organism from a past geological age. Moreover, radioactive decay is a natural process by which an unstable atomic nucleus loses energy by emitting radiation. C-14 (Carbon 14) is a radioactive isotope of carbon that emits radiation which is widely used for dating fossils. C14 decays into the stable isotope C 12 and this radioactive isotope (C-14) has a half-life of 5730 yrs, thereby it is possible to use this rate of decay in order to calculate the age of an object according to the proportion of C14 remaining. The short half-life of C-14 indicates that this radioactive isotope cannot be used to date extremely old fossils (after 50,000-70,000 years, the C-14 dating method is no longer valuable for estimating the age).

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.