wt.epm.build.EPMBuildRule (aka BUILD) is what you want to report on.
Role A is the CAD
Role B is the Part
if you want to join the items in the report
You probably should filter latest on Part and/or CAD as you will get a build rule for each version of part and CAD.
The Build ref type will tell you the link type
7 = Owner
2 = Contributing Content
6 = Contributing Image
4 = Image
If you would like to see content link, then you need a separate report on wt.epm.structure.EPMDescribeLink (AKA EPM Describe Link)
roles are reversed compared to build
role A is the part
role b in the CAD