Depletion is the process of allocating the cost of an

First of all, regarding to this question,
1. Charge(noun or verb) can be used with prepostion with, for, and to. In my opinion, "charge to+ somebody or account such as, checking account" are used for express meaning that some duty is imposed to some body, whereas "charge for+something" means expense or pay for acquring someting. Therefore, in this question, "charge for" might be correct, because "industry charge for earning income."
2. I think that in this question, "as" does not mean because, but means "during the course of operation, more reduced"
Hence, I think "c" would be correct.

Second, I am an international, therefore, it is not easy to distinguish correct pronoun. I might have seen the question that require me to distinguish "through" from "by" or "by means of".
Who does explain about the difference?

Thanks

my FA is A

There does not seem (to me!) to be any mistake in the given sentence

D it is
"charge to" means "charged against income"
I believe what Stolyar meant by (c) is copyright which can be typed as
CTRL+ALT+C = ©
Hmm, seems like it works only in word documents.
Yes Praet, depletion is the equivalent of depreciation but it applies mainly to natural resources which can be depleted (lumber, natural gas, oil) whereas depreciation applies mainly to financial assets

D for me.
systematic charges to income --> attributed to or put on an account of.
Depletion links to reduction in supply of assets in the course.

Yes, it is D. I took it from my financial accounting lessons, which I attended as a pre-MBA practice. BTW, there is yet another form of allocating costs against income—amortization. This term is applied when we deal with intangible assets, such as goodwill, patents, or copyrights.

For those who are interested, I can give a small example of amortization: On 1/1/2004 company buys a certain patent for $60 000. Its useful life is 10 years; the annual amortization is therefore $6000. The entries in 2004 will be:

1/1/2004

Patent 60 000
Cash 60 000
To record costs of acquiring patent

12/31/2004

Patent Expense (Amortization) 6000
Patent 6000
To record patent amortization