Which of the following is the most effective method for administering ventilations to an apneic patient?

The two person bag-valve-mask is the most effective method to administer ventilations with a BVM; however, it is not always practical for field application due to limited resources and limited space. The use of mouth to mask ventilations is also identified as a viable form of artificial ventilations, but the risk of cross contamination in mouth to mouth ventilations renders it less desirable to health care providers.