Identify the subject, verb, Object
Formal writing shows writers' critical thinking.
Verb- critical thinking
Subject-writers
Object-writers'
All are incorrect.
Study these to learn how to recognize subjects and verbs and direct objects. Then try again. Do not guess!
http://www.chompchomp.com/terms/subject.htm
http://www.chompchomp.com/terms/verb.htm
http://www.chompchomp.com/terms/directobject.htm
Subject: writers
Verb: shows
Object: critical thinking