In order to recommend items to users using a bigraph, we necessary need to know $($select all that apply$)$:

Select one or more:

a$.$

The set of items and the set of users

b$.$

User$-$item interactions

c$.$

Contextual factors about the items

d$.$

Low$-$level content features about the items

e$.$

The date at which users interacted with the items