Which of the following transactions is most likely to be fully deductible as a business expense?

(a) Legal costs of $18,600 for purchasing a new business.

(b) Stationery supplies of $600 purchased by a registered charity. The charity is exempt from tax on their income under s CW 41 Income Tax Act 2007.

(c) Replacing the roof on a business’s office block. The roof costs $25,600 and replaces the iron roof with long run roofing. The value of the building on the books is $143,800.

(d) Costs of $5,000 for a fine imposed by government for breaching a resource consent and dumping toxic waste.

please explain why the chosen answer is correct and why the other ones are incorrect.