Final answer:
Under Basel III regulations, the Leverage Ratio was introduced as a non-risk-based measure to ensure banks maintained a sufficient level of capital relative to their exposures. The Countercyclical Capital Buffer was also introduced in Basel III, while Tier 3 Capital, which existed under Basel II, was eliminated.
Step-by-step explanation:
Among the options provided within your question, the feature that was first introduced with the Basel III regulations is the Leverage Ratio. Basel III, a set of international banking regulations developed by the Basel Committee on Banking Supervision, was established to strengthen the regulation, supervision, and risk management within the banking sector following the financial crisis of 2007-2008.
The Leverage Ratio is a measure that was introduced to constrain the build-up of leverage in the banking sector, ensuring that banks have a sufficient level of capital relative to their overall exposures. It represents a non-risk-based measure that banks must uphold regardless of the risk profile of their assets. The Countercyclical Capital Buffer is also a component of Basel III; it's designed to allow national regulators to require banks to hold additional capital during periods of high credit growth to guard against system-wide risks. As for 'Tier 3 Capital,' it does not exist within the Basel III framework; instead, Basel II included a Tier 3 capital measure, which was eliminated under Basel III.