* Analyze the Data and Logic:
Activity 9004 ("Valve House Embankment"): This activity has a direct Finish-to-Start (FS) relationship with Activity 10002, with a lag of 7 days.
Late Start (LS) and Late Finish (LF): In backward pass calculations, the late finish of the successor activity is adjusted for lag and task duration to determine the late start of the predecessor activity.
* Formula for Late Finish (LF):
The Late Finish of Activity 9004 is derived by taking the Late Start (LS) of Activity 10002, subtracting the lag of 7 days, and subtracting 1 day to calculate the exact finish date.
* Correct Date Calculation:
Given the Late Start (LS) of Activity 10002:
LS.10002 = 11-28-03.
Apply the formula:
LF.9004 = LS.10002 - Lag.7 - 1 day = 11-28-03 - 7 days - 1 day = 11-20-03.
* Cross-Verification with Answer Options:
Option A: Incorrect. Misrepresents the formula.
Option B: Incorrect. Incorrect application of logic and lag adjustments.
Option C: Incorrect. Omits the correct lag consideration.
Option D: Correct. Matches both formula and calculated date.