Changing Stability » Advection Question

This image shows a map of the Coterminous U.S. (CONUS) with a hypothetical cyclone and associated warm and cold fronts. Idealized soundings (1000-700 hPa) are shown for air masses in relation to the fronts. Use the graphic to answer the following questions:
With passage of the cold front, will the low-level atmosphere become more or less stable?
With passage of the warm front, will the low-level atmosphere become more or less stable?