Which of the following is NOT correct regarding relationships between variables?

	a.	Relationships involving income statement accounts tend to be more predictable than relationships involving only balance sheet accounts
	b.	Relationships based on industry data are more stable than those based on internal data.
	c.	Relationships in a stable environment are usually more predictable than relationships in a dynamic or unstable environment.
	d.	Relationships involving transactions subject to management discretion may be less predictable.