All of following should be done by the project manager during project control EXCEPT ______.

A) determine that a change has occurred
B) ensure that a change is agreed
C) make sure all changes are approved by management
D) manage changes as they occur

无缝线路低温铺设轨条时，拉伸不到位或拉伸不均匀，必须做好放散或调整锁定轨温的工作。