The answer for Question 3 is that it conveys the idea that an open mind has limitless potential as portrayed through the following line: ''where the clear stream of reason has not lost its way into the dreary desert of sand of death habit(...) and into the heaven of freedom''.
Which clearly states that the correct answer for question 4 is ''clear stream of reason'' which is imagery that allures to our train of thought.
For question 5 the answer is C) It appeals to the readers' sense of adventure by describing a situation that is vastly different from what is familiar. The reason being that throughout the poem the author continously depicts an utopic society in which our beliefs, thoughts and behaviors are not dictated by what's considered socially acceptable.