用行列式的性質(zhì)證明:
已知Q=,P為非零三階矩陣,PQ=0,則:()
A.當(dāng)t=6時,r(p)=1 B.當(dāng)t=6時,r(p)=2 C.當(dāng)t≠6時,r(p)=1 D.當(dāng)t≠6時,r(p)=2