The only giveaway on this chart is the direction of the "feathers" on the wind arrow. Irrespective of hemisphere, feathers point towards the low pressure so D is definitely a low (or a depression). If you follow the winds along the isobars, you will see that the wind around the "other" pressure system is also flowing anticlockwise (as with zone D) so this must be a low as well. Hence A is a trough, an extension of low pressure. If the areas around A and D are lows, then the area south of C must be a high, and so C itself is an extension of high pressure: a ridge. Finally, B is in the area between high and low pressures. It is a col.