“WAS” is the Linking Verb, “NORA WHO SUGGESTED WE CLEAN IT UP” is the Subject Complement.
Step-by-step explanation:
Subject Complement is a word or a phrase that comes immediately after the Linking Verb giving additional or further information about the subject.
Linking verbs which are also the connecting verbs link a subject with what the SUBJECT IS, i.e. these verbs describe a subject. Linking verbs do not tell us about the action of the subject.
The most common linking verbs are the BE form, i.e., is, are, am, become, was, were, are being, has been, seem etc. There are other forms that can play the role of linking verbs, i.e., they can act as linking verbs as well as action verbs. For example: appear, taste, smell