A survey of the master cast shows that the 3.5 and 3.7 abutments for a fixed partial denture have different paths of insertion with respect to 3.7. A semi-precision attachment is chosen rather than preparing the teeth again. Where should the male part of the attachment ideally be located?

Mesial of the 3.6 pontic.

Distal of the 3.5 retainer.

Distal of the 3.6 pontic.

Mesial of the 3.7 retainer.