一棵二叉树第六层(根结点为第一层)的结点数最多为______个。

A company acquires a manufacturing facility in which it will produce toxic chemicals. The cost of the facility (exclusive of the underlying land) is $ 25 million and it is expected to provide a 10-year useful life, after which time the company will demolish the building and restore the underlying land. The cost of this restoration and cleanup is estimated to be $3 million at that time. The facility will be amortized on a straight-line basis. The company’s discount rate associated with this obligation is 6.25 percent. The total expense that will be recorded in the first year associated with the asset retirement obligation on this property is closest to:（）

A. $163618.

B. $224945.

C. $265880.