Need what describes using organisms that were only alive during a specific time period to estimate the unknown age of items? radioactive dating law of superposition relative dating index fossils

It’s index fossils, sry you had to wait 3 hours

Ithink the answer is b

The us is first  the  u.s. economy  remains the  largest in the world  in terms of nominal  gdp. however, the  u.s. economy  loses its spot as the number one  economy  to china when  measured  in terms of  gdp  based on ppp. in these terms, china's  gdp  is $23.19 trillion exceeds the  u.s. gdp  of $19.42 trillion