Correct option is D
Statement-I is incorrect.
In the event of a default, holders of US Treasury Bonds would still retain their legal claims to receive payments. A default indicates that the government is unable to meet its payment obligations as scheduled, but it does not eliminate the bondholders' legal rights to the payments. Bondholders could still pursue legal action or seek payment, though they may encounter delays or receive reduced payments.
Statement-II is correct.
US government debt, such as Treasury Bonds, is not backed by physical assets like gold or land. Instead, it is backed by the "full faith and credit" of the US government, which means the government's ability to tax and generate revenue to meet its debt obligations.