Which of the following is a technique used in relative dating?

Beta decay
Index fossil correlation
Isotope ratios
Radiocarbon dating

is it d pls help me

3 answers

Yes, d.
I would pick C

Radiocarbon dating is usually for absolute age, but comparing samples you are likely to use ratios , perhaps even of C14 again.
see:
http://www.parks.ca.gov/?page_id=24000
d is incorrect