So that they would not forget to take action on the topic, or forget about the topic entirely. Hope this helps!
1.hiking
2. putting
3. seeking
4. traveled
5. mapped
6. offered
7. wandering
8. becoming
9. visiting
10. phoning
11. checking
That's all that I can see
I am not completely sure but I will go with c. I will read the book, but I haven't started it. I am truly sorry if you get this wrong.
my answer here would be option C. considering it pretty well sums of the definition of both primary and secondary sources