Final answer:
The sentence suggesting the narrator's lack of confidence is 'The text also shows little to no evidence of the writer's intent to meet or challenge conventional expectations in rhetorically effective ways,' which expresses doubt in meeting writing standards.
Step-by-step explanation:
To determine which sentence from the text suggests that the narrator is not very confident about the quality of his own work, we should look for phrases that indicate doubt or a lack of achievement in the writing standards. The most telling sentence in this context would be: The text also shows little to no evidence of the writer's intent to meet or challenge conventional expectations in rhetorically effective ways. This sentence shows a clear admission of not fulfilling the expected writing criteria, demonstrating a strong sense of the narrator's insecurities regarding his work. Additionally, the sentence The author demonstrates little, if any, familiarity with the technical language associated with visual rhetoric further suggests that the narrator is not confident, as it discloses a lack of understanding of essential writing concepts.