Final answer:
Without access to the specific text referencing Mr. Plateas in paragraph 7, it's not possible to analyze the character development. Usually, character development is explored through traits, motivations, and conflicts presented by the author in the narrative.
Step-by-step explanation:
To discern character development for Mr. Plateas in paragraph 7, one must analyze the description and actions provided by the author. Unfortunately, as there is no provided paragraph 7 specific to a character named Mr. Plateas in the provided reference texts, it would be speculative to create an analysis without the relevant excerpt. Normally, to evaluate a character's development, one would examine their thoughts, actions, descriptions, and interactions within that specific paragraph to understand their role and evolution within the narrative. This would include considering factors like character traits, motivations, and conflicts that contribute to their complexity and depth.