Final answer:
James Madison played the biggest role in planning and writing the Virginia Plan.
Step-by-step explanation:
The delegate who played the biggest role in planning and writing the Virginia Plan was James Madison (b).
James Madison was an important participant in the Constitutional Convention and authored many of The Federalist Papers, which advocated for the Constitution's ratification. He was a strong supporter of a strong national government and played a key role in the development of the Virginia Plan, which served as the basis for the Constitution.