Final answer:
When facing a 'killer B', or potential error in your work, writing it down on a piece of paper is the recommended action so you can address it properly later without distraction.
Step-by-step explanation:
The term "killer B" is a metaphor used to describe a potential distraction or mistake in your work. The options provided suggest different ways of dealing with this metaphorical 'killer B'. When you encounter a "killer B", or a possible error, in your work, the best course of action is to write it down on a piece of paper. This way, you can address the error properly later without forgetting it or allowing it to distract you from the task at hand. Handling it immediately may not always be efficient, particularly if you are in the middle of something else that requires your concentration. Ignoring it completely is not advisable as this could lead to an accumulation of errors. Therefore, option 3 is the most appropriate method. It's important to note that "killer Bs" should eventually be dealt with to ensure the quality of your work.