When Dan Sees Three Objects,sometimes He Counts Them as "1,2,5",sometimes

When Dan sees three objects,sometimes he counts them as "1,2,5",sometimes as "1,2,b",and other times as "2,1,a".Dan

A) appears to have mastered the one-to-one principle and the stable-order principle.
B) appears to have mastered the one-to-one-principle but not the stable-order principle.
C) appears to have mastered the stable-order principle but not the one-to-one principle.
D) does not appear to have mastered the one-to-one principle or the stable-order principle.