Question

If the president vetoes a bill, the
executive branch can override the veto with a 2/3 vote
legislative branch can override the veto with a 2/3 vote
executive branch can appeal the veto to the Supreme Court
legislative branch can appeal the veto to the Supreme Court

Answer 1

If the president vetoes a bill, the "legislative branch can override the veto with a 2/3 vote," since this is one of the ways in which the legislative branch acts as a "check" to executive power.