1. Which of the following is the best example of a narrative?

a blog post on the issue of mandatory community service
a wiki-post on Julius Caesar’s epilepsy
a memoir about growing up with a disability
a biography of Amelia Earhart

2. An important element that explanatory writing should employ in order to create credibility with the readers is ____.

deductive reasoning
research
cohesive transitions
addressing counterarguments

For the first question, though it could be confusing, writing a memoir is a narrative in its purest form, because it demands that the author tells the reader everything that's done in his/her life everyday, and as it's somehow a personal communication, the writer narrates his/her life in detail. However, a biography, for example, being narrated in first person, could also be a narrative, but as it's not a autobiography (in this case) therefore it is not.

For the second question, although all four elements mentioned are, in fact, important, the one that helps create credibility is the research, as a support for the main purpose of the explanatory texts (Showing the knowledge of one topic). Nevertheless, cohesive transitions are really important for making the text more friendly for the reader and also easy to understand.