Which Technique Has Been Used for the Past 35 Years

Which technique has been used for the past 35 years to attempt to measure solar neutrinos?

A) proton-proton reaction in which neutrinos play an intermediate role
B) interaction of neutrinos with water molecules in huge underground tanks
C) production of radioactive argon nuclei by neutrino interaction with chlorine nuclei in deep underground tanks
D) interactions of neutrinos with radioactive argon nuclei to produce chlorine nuclei, which are then measured chemically