Bank offers secured loans to three of its customers. To Customer 1, Bank provides a $1,000 loan and takes a security interest in a piece of collateral valued at $500. Bank lends $20,000 to Customer 2 and takes a security interest in a $1 million piece of collateral. Finally, Bank gives Customer 3 a $100,000 advance and receives a security interest in a piece of collateral valued at $100,000. Based upon the amounts loaned and the value of the collateral, which of these transactions is valid under Article 9?

	a.	Only the transaction with Customer 3 is valid because the value of collateral equals the loaned amount.
	b.	Only the transactions with Customers 1 and 3 are valid because the collateral is of equal or lesser value than the loaned amount.
	c.	Only the transactions with Customers 2 and 3 are valid as the collateral is of equal or greater value than the loaned amount.
	d.	All the transactions are valid, as there is no prescribed ratio relating to the amount loaned and the value of the collateral under Article 9.