Which of the following helps reduce the flow of thermal energy from within your house to the outside? A.) High efficiency appliances
B.) Attic insulation
C.) Use of solar energy instead of fossil fuels

Should be B. It is talking about reducing thermal energy from transferring, so insulation is the only thing that helps. High efficiency appliances saves you electricity, and C is talking about renewable energy.

a polar bond is formed when electrons are shared unevenly between atoms