Please I need a brief explanation of the answer

15. Which of the following items would be a violation of materiality?

a.	a company did not separately report an unusual gain of $50,000. Its income from operations was $5,000,000
b.	a company expensed the purchase of pencil sharpeners that have an estimated useful life of three years
c.	a $25,000 illegal bribe to a foreign official was not separately disclosed in the annual report.
d.	a $5,000 expenditure to improve a building that originally cost $5,000,000 was expensed