What is the best answer for the missing definition below in the formula for return?

CF_t + (P_E - P_B) CF_t + PC

R = -------------- = ---------

P_B P_B

where

CF_t = ______________________________________________

P_E = Price at end of period t (or sale price)

P_B = Price at beginning of the period (or purchase price)

PC = Change in price during the period

Select one:

a. Cash flows paid during measurement period t

b. Cash flows over life of project

c. Future value of cash flows paid at time t

d. Future value of interest payments paid at time t