Place cells remap to give each environment its own code

Correct: B — Place cells 'remap' — many become silent, others develop new place fields, producing a near-orthogonal population code per environment

Muller & Kubie (1987) showed that when rats move between two distinct boxes, hippocampal place cells dramatically reorganize: some that fired in box A go silent in box B, others develop entirely new place fields, and the spatial overlap of active cells between environments approaches chance. This 'remapping' produces a separate, near-orthogonal population code for each environment — a substrate for pattern separation that lets the same hippocampus represent many similar places without confusing them. Subtler global remapping (similar cells, different rates) versus complete remapping (different cells) was later distinguished by Leutgeb et al. (2005).