How Does the Cosmological Constant Differ from Quintessence

Multiple Choice

How does the cosmological constant differ from quintessence?

A) The cosmological constant is a specific physical effect that can be described mathematically, whereas quintessence is the total of all indefinable properties that make the universe what it is at any given time.
B) The cosmological constant provides an accelerating force in the universal expansion, whereas quintessence provides a decelerating term; it is the balance between the cosmological constant and quintessence that determines whether the expansion accelerates or decelerates.
C) There is essentially no difference; basically, quintessence is the modern name for the cosmological constant.
D) The cosmological constant provides a constant accelerating force in the universal expansion, whereas quintessence can change as the expansion proceeds.