Question

which of the following are caused when plaque is not adequately removed from the surface of the tooth

Answer 1

From what I learned, I can say if plaque is not adequately removed from the surface of the tooth, it can cause:
Tooth decay 
periodontal diseases ( bacterial infection of the gums)
Halitosis or bad breath 

Answer 2

You will be at risk of tooth decay, cavities, worse breath than usual that is tough to get rid of. :)