. () For what target of providing mice medicines in the experiments?

A、Tofindwhichaspectreducestherunner'shighsymptoms.
B、Topredicttheresultsofthespecificsignoftherunner'shigh.
C、Toidentifywhatdeterminesthereasonforhappinessinthebody.
D、Totestwhataffectsthelevelofthechemicalsrelatedtohappiness.