Identify the transition in this sentence: "however, as you see, I did not go to join Kurtz there and then."

The transition word "However" serves a specific purpose in the sentence, establishing a contrast or presenting an exception to what may have been previously stated. In this context, it indicates that the speaker is acknowledging a potential expectation — that joining Kurtz might have been a logical or anticipated action — but is then highlighting that they did not take that action.

Using "However" effectively signals to the reader that the speaker is addressing an aspect that might differ from previous information or assumptions. This word enriches the sentence by providing a smoother flow of ideas, marking a shift in the direction of the argument or narrative. The other options do not fulfill this role of establishing contrast; for instance, "And" and "Thus" are more about continuity or consequence rather than opposition. "Therefore" indicates a conclusion drawn from preceding statements, which is not the case in this particular sentence. Thus, "However" is the most appropriate transition for conveying the intended meaning.