Answer:
a- personal letters written by Gandhi.
Step-by-step explanation:
The best source that students could have in order to learn about the thoughts and feelings of Gandhi would be his personal letters. In his letters, Gandhi most likely expresses his most honest thoughts. This is usually true because letters are intended to be used in daily life, not read by a large audience. This means that the authors are usually more honest and open in them than they would be in other sources.