The financial instruments that generate proceeds for investment in environmentally sustainable and climate-suitable projects are called as:

Green Bonds are fixed-income debt instruments specifically earmarked to raise capital for projects with positive environmental and climate benefits, such as renewable energy, energy efficiency, sustainable transport, and climate adaptation. India's Sovereign Green Bonds were first issued in January 2023. 'Carbon Bonds' and 'Climate Credit Bonds' are not standard financial instrument names. Social Impact Bonds finance social programs (not specifically environmental). Hence option (a) is correct.