Final answer:
In Broadbent's model of attention, the attended message enters at the point when it moves from the sensory memory to the filter.
Step-by-step explanation:
The question asks at which point in Broadbent's model of attention the attended message enters. According to Broadbent's model, which was one of the first cognitive models to describe the process of auditory attention, the attended message enters when moving from the sensory memory to the filter. Thereafter, only the information that passes through the filter reaches the detector and can then be processed for storage in memory. Therefore, the correct answer is b. When going from sensory memory to the filter.