Look at the outline of the US Constitution below: The US Constitution

I.
II. Article I: The Legislative Branch
A. Section 1
B. Section 2
C. Section 3
D. Section 4
E. Section 5
F. Section 6
G. Section 7
H. Section 8
I. Section 9
J. Section 10
III. Article II:
A. Section 1
B. Section 2
C. Section 3
D. Section 4
IV. Article III: The Judicial Branch
A. Section 1
B. Section 2
C. Section 3
V. Article IV: The States
A. Section 1
B. Section 2
C. Section 3
D. Section 4
VI. Article V: Amending the Constitution
VII. Article VI: The Supremacy Clause
VIII. Article VII: Ratification
IX. The and Amendments

Which of the following correctly completes line I. in the outline above?

A. Bill of Rights
B. The Preamble
C. Checks and Balances
D. The Executive Branch