Question: What Precedent Was Established by the Crisis Surrounding Andrew

Question: What precedent was established by the crisis surrounding Andrew Johnson's impeachment?

A) The president can only be removed from office for criminal actions, not for political disagreements with Congress.
B) The president pro tem of the Senate is next in the line of succession if the president is removed from office.
C) One-half of the Senate must find the president guilty during his impeachment trial if he or she is to be removed from office.
D) Three-quarters of the members of the House of Representatives must vote to impeach the president for his or her case to be referred to the Senate for trial.