"The Sensation of Thirst Often Lags Behind the Need for Water

"The sensation of thirst often lags behind the need for water." What is being described?

A) a reason why short-term water-balance can be difficult to maintain.
B) a reason why an athlete can easily regulate water intake during competition.
C) a reason why fever is does not impact water balance
D) a reason why there is a powerful urge to drink