The correct answer for the given question is option 'A', which states that the speaker should stand aside and watch the snake pass. Let's understand why this is the correct answer.

Understanding the Situation:
The given scenario describes a snake wiggling in the grass. It is essential to respond appropriately to ensure safety and avoid any harm from the snake. Let's analyze the different options provided and why option 'A' is the most suitable choice.

Option 'A': Stand aside and watch him to pass
By standing aside and watching the snake pass, the speaker maintains a safe distance from the snake. This option allows the speaker to observe the snake's behavior and ensure that they do not pose a threat. By staying calm and collected, the speaker can make informed decisions based on the snake's movements.

Option 'B': Hide behind the tree
Hiding behind a tree may initially seem like a safe option, but it has its drawbacks. While hiding, the speaker may not have a clear view of the snake's movements. This lack of visibility can lead to potential accidents or misunderstandings about the snake's intentions. It is always better to have a clear line of sight to assess the situation effectively.

Option 'C': Run away to his room
Running away to a room is an extreme overreaction to the presence of a snake in the grass. Snakes usually do not chase or attack humans unless they feel threatened. Running away can startle the snake and potentially provoke it. Additionally, locking oneself in a room does not guarantee safety, as the snake may still find its way inside. It is better to handle the situation with caution and without panicking.

Option 'D': All of the above
This option is incorrect because hiding behind a tree and running away to a room are not appropriate reactions to the situation. Both of these options may lead to unnecessary panic and potentially dangerous consequences. Standing aside and watching the snake pass is a more sensible and safe approach.

Conclusion:
In conclusion, when encountering a snake wiggling in the grass, the most suitable response is to stand aside and watch it pass, as mentioned in option 'A'. This allows the speaker to maintain a safe distance, observe the snake's behavior, and make informed decisions accordingly.