The primacy effect refers to:

The primacy effect is a cognitive phenomenon observed in memory studies where individuals exhibit a greater recall of the first items presented in a list. This occurs because the initial items benefit from more cognitive processing time—they are often rehearsed more and enter long-term memory more effectively than subsequent items. This enhanced memory for the early items is in contrast to the recency effect, which refers to the superior recall for items at the end of a list.

In this context, while other options address different aspects of memory, they do not relate to the primacy effect specifically. For instance, the last items in a list relate to the recency effect, which is distinct from the early items. Memory for items in the middle of the list is generally lower due to interference from both the first and last items. Enhanced recall of visual information over verbal does not pertain to the concept of primacy at all, as it addresses different modalities of memory rather than the order of information presented. Thus, option B correctly identifies the primacy effect as the tendency to remember the first items in a list better.