Refer to figure.
A difficult question as there are 2 possible scenarios being asked:

1. The formation of the vortex - outward along the span under the wing, then upwards around the wingtip towards the lower pressure above the wing.

2. The path of the vortices once formed - outwards and downwards from the wing tips, descending typically 1000 ft over 3 minutes before dissipating.

Feedback over several years confirms the examiner is asking about the first scenario - the formation of the vortices.

WAKE TURBULENCE

Whenever an airplane generates lift, air spills over the wing tips from the high pressure areas below the wings to the low pressure areas above them. This flow causes rapidly rotating whirlpools of air called wingtip vortices. An aircraft generates vortices from the moment it rotates on take-off to touchdown.
The intensity depends on aircraft weight, speed and configuration. The greatest wake turbulence danger is produced by large, heavy airplanes operating at low speeds, high angles of attack and in a clean configuration.
Although wake turbulence settles, it persists in the air for several minutes, depending on wind conditions. In calm winds, wing tip vortices separate outwards on each side of the runway. In light winds of 3 to 7 knots, the vortices can stay in the touchdown area, sink into your take-off or landing path, or drift over a parallel runway.

General Guides:

• To avoid turbulence when landing behind a large aircraft, stay above the large airplane’s glide path and land beyond its touchdown point.
• If a large airplane has just taken-off as you approach, touch down well before the large aircraft’s lift-off point.
• When departing after a large aircraft has landed, lift-off beyond its touchdown location.
• When taking-off behind a large aircraft, lift-off before the large aircraft’s rotation point and climb out above or upwind of its flight path.