Answer:
A. using a desktop computer as opposed to a laptop.
Step-by-step explanation:
In such questions, it is usually important to consider all given options. Here, consolidating errands will reduce gasoline use which is good for environment, replacing incandescent bulbs with compact fluorescent bulbs will use less electricity so this is also good as coal power plants produce a lot of carbon, then using a power strip for electronics is also good as it is plugged to only one socket and hence saves electricity as we often leave devices plugged to different sockets which keeps drawing electricity and lastly, lowering thermostats during cold months is also good as low temperature requires less heating and less electricity. This leaves option A which does not have any effect on electricity consumption.