Which seismic design category corresponds to a low seismic risk level?

The seismic design category that corresponds to a low seismic risk level is indeed the correct answer. In seismic design codes, particularly those established by the International Building Code (IBC) and ASCE 7, the seismic design categories are classified from A to F, with Category A representing the lowest seismic risk and Category F representing the highest.

Category A is designated for regions where the likelihood of experiencing seismic events is minimal, and buildings in this category are typically not required to incorporate extensive seismic design measures. While Category B indeed indicates a low seismic risk, it is more appropriate to refer to Category A as the one with the very least seismic risk.

The progression of categories indicates increasing risk levels and thus correlates to stricter design requirements. Hence, while Category B is still low in seismic risk, it is not the lowest; that distinction belongs to Category A. Understanding these categories is crucial for engineers in determining the appropriate design specifications for structures based on regional seismic considerations.