Which of the following BEST describes the relationship between portfolios, projects, and programs?

A. A group of programs makes up a project, and all of an organization's projects make up a portfolio.
B. A group of projects makes up a program, and all of an organization's programs make up a portfolio.
C. A group of portfolios makes up a program, and all of an organization's programs make up a project.
D. A group of projects makes up a portfolio, and all of an organization's portfolios make up a program.