In a Multifactor Model, What Does the Time Horizon Risk

In a multifactor model, what does the time horizon risk represent?

A) Unanticipated changes in the level of overall business activity.
B) Unanticipated changes in investors' desired time to receive payouts.
C) Unanticipated changes in short term and long term inflation rates.
D) Unanticipated changes in the willingness of investors to take on investment risk.
E) None of the above.