The owner (buyer) of a project usually has the right to direct changes to the scope of work while the project work is being accomplished. Often, the owner will orally request a change and insist that the change be initiated immediately without the normal documentation (e.g.a change order). When the change be initiated without documentation ______.

A) the owner assumes all responsibility for paying for the change although the owner may at a later not want the change
B) the owner assumes responsibility for one-half the cost of the change until the documentation is completed and all at the same time
C) the project manager assumes all risk for the change, if initiated, until the documentation is received
D) the project manager assumes only the risk of misinterpreting the owner's oral change directive, while the owner assumes responsibility for paying for the request change

井工开采时，厚度为3.0m的煤层是煤层。（）

A．薄煤层；

B．中厚煤层；

C．厚煤层；

D．特厚煤层。