Answer:
There are four activities on the critical path, and they have standard deviations of 1, 2, 4, and 2 days. The standard deviation of the critical path is:
C. 9.
Step-by-step explanation:
The implication is that the standard deviation of the critical path is the sum of the standard deviations of the four activities on the critical path. This sums to 9 days (1 + 2 + 4 + 2), implying that the critical path varies from the mean days of critical path activities by 9 days plus or minus.