1. B. Complete Subject
The complete subject tells us who or what the sentence is about.
Example:
All people change their environment
All people is the complete subject

2. C. Complete Predicate
The complete predicate tells us what the subject is doing or who the subject is.
The complete predicate always begins with a verb.
Example: All people change their
environment.
Change their environment is the complete predicate

3. Conclusion
Every sentence must have a complete subject and complete predicate in order to make the sentence complete.
Tom Brady is the quarterback for the New England Patriots.
What is the complete subject and predicate of this sentence?