This phrase is in reference to how Atticus dealt with Mayella on the stand during Tom Robinson's trial. Mayella testified that Tom Robinson raped her and beat her up. During his questioning, Atticus found holes in Mayella's story. He got her confused and made her sound as though she wasn't sure about the details or that she wasn't as strong of a person as she'd like to be. This made it difficult for Mayella to twist the truth to make Tom Robinson seem guilty so she stopped talking. She gave some testimony and then quit answering questions all together. Unfortunately, even though Atticus's questioning of Mayella revealed some significant inconsistencies and improbabilities the jury still convicted Tom Robinson because of his race.
I had to look for the missing passage and the options and here is the answer:"Here is New York" is a book that was written by E. B. White and Roger Angell. And based on the passage taken from this book, the effect that the symbol has on the meaning on this passage is this: The commuter is the queerest bird of all. The suburb he inhabits has no essential vitality of its own and is a mere roost where he comes at day’s end to go to sleep. (This answer is based on the actual options attached to this question).
I believe the word means being cautious in this context.
