Ice dams are most directly related to:

(A) the installation of soffit vents and ridge vents.

(B) heated air in an uninsulated, unvented attic.

(C) the addition of vent spacers in rafter bays.

(D) a roof having gutters.

(E) a house having gable vents.

(B) heated air in an uninsulated, unvented attic.

Explanation:

-Ice dams are formed by an interaction between snow cover, outside temperatures, and heat lost through the roof - more specifically, from heat loss through the poorly insulated ceiling of the house into the attic area and under the roof.

-Hot, humid air trapped in attics can also cause moisture to accumulate, resulting in mold or mildew.