I would say that the answer should be "Helen's challenges with the frustration of learning to communicate".as a blind-deaf person and the excellent analogy with being shrouded in fog and not having how to determine where she was headed but love giving her the light to find her way and eventually get a degree at university.
The correct answer is the last option.
To credit a source means to ACKNOWLEDGE WHERE YOU FOUND A SOURCE. In order to avoid plagiarism, the writer has to cite the sources where he found information, being the most common citation formats APA or MLA. The citation style to use will depend on the topic to discuss in the paper.
1. American revolution
2. French Revolution
3. Stamp Tax
4. French American War
5. British impression of sailors
Hope this helped!!