Contrasting Mission and Vision Statements

What is the difference between a mission statement and a vision statement?

a. A mission statement is a declaration about the future, whereas a vision statement explains the organization's purpose
b. A mission statement explains the company's purpose, whereas a vision statement is a declaration about the future.
c. A mission statement is a declaration about the future, whereas a vision statement is used to create the company's business ethics.
d. A mission statement explains the company's purpose, whereas a vision statement is used to create the company's business ethics.