The Fungal Cross Ad,pan × +,+ (Where Ad and Pan

The fungal cross ad,pan × +,+ (where ad and pan are two linked loci) gave only the following two types of tetrads: $$\begin{array} { l l l } & \text { Tetrad I } & \text { Tetrad 2 } \\\text { Spore 1 } & \text { ad,pan } & a d , \text { pan } \\\text { Spore 2 } & \text { aborted } & a d ,+ \\\text { Spore 3 } & \text { aborted } & +,\text { pan } \\\text { Spore 4 } & + _ { + } + & + ,+\end{array}$$
These results suggest:

A) a deletion in the wild-type parent.
B) a duplication in one or both parents.
C) an inversion in one of the parents.
D) a translocation in one of the parents,with adjacent segregation.
E) a translocation in one of the parents,with alternate segregation.