Answer:
For President Lincoln to grant them a fully pardon:
A. They had to take an oath.
Step-by-step explanation:
According to the Proclamation of Amnesty, Lincoln is pardoning the people involved in the rebellion with one condition: that they take an oath. Not only must they take it, they must also never break such oath. Even though Lincoln mentions property and slaves, those were not optional conditions for the people to be pardoned. They had no power to decide about whether or not to free their slaves, for instance. However, the oath was still optional. If someone refused to do it, they would not be pardoned.