Final answer:
The accounting concepts violated in each situation are: Consistency, Materiality, and Accrual Accounting.
Step-by-step explanation:
A) The accounting concept that was violated in situation A is Consistency. Consistency refers to the use of the same accounting methods and principles from one period to another.
B) The accounting concept that was violated in situation B is Materiality. Materiality relates to the importance or significance of an item or event in the financial statements.
C) The accounting concept that was violated in situation C is Accrual Accounting. Accrual accounting is the recognition of revenues and expenses when they are earned or incurred, regardless of when the cash is received or paid.