Which of the following statements is (are) correct?

a. Accumulated depreciation represents a cash fund being accumulated for the replacement of plant assets.

b. The cost of a machine includes the cost of repairing damage to the machine during the installation process.

c. A company may use different depreciation methods in its financial statements and its income tax return.

d. The use of an accelerated depreciation method causes an asset to wear out more quickly than does use of the straight-line method.