You are on a heading of 270 degrees. ATC issues this traffic advisory, "Traffic one o'clock, two miles southbound." Where should you look?

To determine where to look after receiving the traffic advisory of "Traffic one o'clock, two miles southbound," it is crucial to understand the concept of relative positions in navigation.

In aviation, "one o'clock" refers to a position that is 30 degrees to the right of your current heading. Since the aircraft is on a heading of 270 degrees (which is due west), the "one o'clock" position will be to the right or towards the north. The two-mile distance indicated informs you how far away the traffic is. Therefore, since the traffic is also described as "southbound," it is moving toward 180 degrees, which is generally the opposite direction of your traversal.

Given these details, the correct answer indicates that you should look to your left (which would be towards the north-west), to spot traffic at one o'clock while you are moving westward at a heading of 270 degrees. This positioning allows you to effectively monitor the traffic while also considering its movement direction relative to yours.