Which Schedule compression technique has phases or activities done in parallel that would normally have been done sequentially

A.
Crashing

B.
Fast Tracking

C.
Leads and lags adjustment

D.
Parallel task development

Explanation:
Fast tracking means that you look at activities that are normally done in sequence and assign them instead partially in parallel. If you were fast-tracking, you would start constructing the solution in areas where you felt the design was pretty solid without waiting for the entire design to be completed.

“Crashing” the schedule means to throw additional resources to the critical path without necessarily getting the highest level of efficiency. For instance, lets say one person was working on a ten-day activity on the critical path. If you were really desperate to shorten this timeframe, you might add a second resource to this activity.

Similarities are:
1) Both the approaches are aimed at reducing the schedule
2) Both the approaches require addition of resources to achieve the goal
3) Even though fast tracking doesn’t mention the term Critical Path, it’s obvious that the Critical Path tasks need to be done in parallel to reduce the schedule. So, both the approaches involve changes to Critical Path activities schedule.