The correct examples of checks and balances from the options provided are:
- The judicial branch can rule a new law unconstitutional.
- The legislative branch can override a veto.
The other options either misstate the powers of the branches or are incorrect. For instance, the executive branch cannot declare war; that power is primarily held by Congress. Also, the judicial branch does not have the power to veto presidential pardons. The executive branch cannot impeach a Supreme Court Justice; rather, it is the legislative branch (specifically, the House of Representatives) that has the power to impeach.