Final answer:
The latest completion time for activity G in a project network cannot be calculated with the provided information, which is not relevant to the question.
Step-by-step explanation:
The question pertains to calculating the latest possible completion time for an activity in a project network, given a project duration of 21 days. Unfortunately, the data provided (options a, b, c, d) do not correspond to project network activities or durations and appear unrelated to the question.
To properly calculate the latest possible completion time for activity G, we would normally use the critical path method and consider the durations of preceding activities, as well as any float times available. The answer to the specific question, given the project duration of 21 days, is not determinable with the provided information. Usually, for activity G’s completion time, we'd need a list of all the activities along with their respective duration times and dependencies.