What Was One Concern That Convinced Enough Moderate Senate Republicans

What was one concern that convinced enough moderate Senate Republicans to not convict Andrew Johnson during his impeachment trial?

A) Removing Johnson as president would do irreparable damage to the constitutional separation of powers.
B) There was no precedent to determine who would succeed Johnson as president if he were removed from office.
C) Removing Johnson as president would result in his home state of Tennessee not ratifying the Fourteenth Amendment.
D) Ulysses S. Grant, who had no political experience, would become the next president.