It would be "b. failure to respond to the committee" that was not <span>a Nixon impeachment charge, since in fact Nixon, once accused, was fairly cooperative with the proceedings. </span>
The Vietnam War showed the US people that the US wasn't the mightiest force on planet and that they were prone to losses as they eventually lsot the war. It created an anti-war sentiment and the American generation didn't want to partake in the actual war for that reason.
To stop the spread of communist or that they got bomed by japan
1 2 3 5 are correct for this problom