The correct answer is option a) Rephrase the implicit evidence so that it becomes explicit.
When doing research on literal pieces, the information is rarely explicit to the reader, as it's on theorical frameworks of research protocols. In the case of implicit statements, the reader may use their background knowledge on the subject in order to paraphrase (reword) the information and present it in an explicit and clear manner in one's own work.
The rest of the options cannot be considered correct since:
b) Authors are unlikely to explain a subject more than once on their work. If they do, the reader must keep in mind that the first time a subject is explained, it will be the most thoroughly explained of all (unless the author states otherwise).
c) It is not possible to make an inference on a subject without prior explicit evidence. The information must be clear and detailed first.
d) To look outside the analysis object most likely aims to encounter reviews or rewordings made by other people. Using these elements as evidence means to support a subject based on someone else's opinion, not the information presented on the literal piece itself. Avoiding this might prevent skipping important details made by the piece's author.