Which statement is correct for the properties of SACF (correlogram) of a stationary and (weakly) dependent time series?

Select one:

a. All of the sample autocorrelations are statistically different from 0

b. A flatter decline of SACF to 0 means a lower degree of dependence on its own past

c. None of the sample autocorrelations are statistically different from 0

d. It shows a quick decline to 0