iF two mEn suspECtED For somE rEAson thEy hAvE A Common AnCEstor, ______ .
A．wE CAn DECiDE ACCorDing to thEir FAmily trEE
B．wE CAn FinD thE truth From thEir gEnEtiC mArkErs
C．wE CAn CompArE thE DiFFErEnCEs in thEir y ChromosomE
D．wE CAn look For writtEn rECorDs to provE thEir rElAtionship