After General Lee surrendered to General Grant, General Grant ordered food sent to Confederate troops. He also allowed them to take their horses and go home. When Union troops were celebrating their victory he stopped them. Why do you think he was showing such kindness to his defeated enemies?

C. To learn from the conclusions of many other experts on the event.

Explanation:

When a person uses primary sources, they are finding out about an event around the period that it happened which means that subsequent related events are not accounted for.

When using secondary sources however, people have most likely had time to review the information and make certain conclusions of the event that gives it more meaning and context. This is therefore one of the main reasons people might use secondary information as opposed to primary.