Which AV approach uses a variety of techniques to spot the characteristics of a virus instead of attempting to make matches?

When you create a template, Excel adds the file extension:

A. .xlsx B. .xltx C. .xmlx

A friend has attempted to install a new wireless printer on a home network. She can print to it when plugged into a USB cable from the laptop to the printer, however, she cannot print wirelessly. You remotely connect to her laptop to troubleshoot the issue. Which of the following is MOST likely the reason that she cannot print wirelessly?

A. The printer does not have an IP address B. The printer is low on toner C. The printer cannot access the network D. The laptop has the wrong print driver installed