Scientists around the world use a standardized taxonomic system. Why would scientists want to use a taxonomic system that is standardized?
A In order to avoid confusion with the identification of organisms
B Because Linnaeus established the system
C So that Latin names can be applied for a practical purpose
D In order to place organisms in different groups

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .

she forgot to record a transaction

the answer to your question is:

c. complementary base-pairing