The correct answer is: D. Expected standard
An expected standard is a standard that is set based on what is expected to be achieved under normal operating conditions. It is a realistic and achievable goal that can be used to measure performance and identify areas for improvement.
A basic standard is a standard that is set based on the minimum acceptable level of performance. It is a lower standard that can be used to identify areas where performance is below expectations.
An ideal standard is a standard that is set based on what is theoretically possible under perfect conditions. It is a very high standard that is not always achievable.
A normal standard is a standard that is set based on what is typically achieved under normal operating conditions. It is a middle ground between a basic standard and an ideal standard.
Expected standards are the most appropriate type of standard for cost control purposes because they are realistic and achievable. They can be used to measure performance and identify areas for improvement.