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Refer to figure.
An aircraft is flying from point A to point B at the flight level corresponding to the pressure surface of the constant pressure chart. Which of the following statements is correct?

  • A

    The true altitude will be higher over A than over B.

  • B

    Wind speed over B is higher than over A.

  • C

    The true altitude will be higher over B than over A.

  • D

    Wind speed over A and over B is the same.

FEW CONSIDERATIONS:

Firstly, it is important to point out that this is a Contour chart and pressure information is not provided - Pressure is constant everywhere => this shows the True Altitude of a certain pressure level. For example, the 500 hPa level corresponds to FL180. Isohypses will show you whether its true altitude is found at a lower or higher level (due to temperature variations). 
Isohypses are are plotted with the reference being MSL and the heights give us an indication of the distance that a pressure level is from MSL. If the contours are high values (wider spaced) then we can assume a high pressure exists. Conversely if the contours are lower values (closely packed) ,then we can assume a low pressure. 
Having that established, it is true that roughly the same rules apply as for isobar charts. The closer the contours the stronger the wind.
Circulation of air around a High and Low Pressure system: 
In the Northern Hemisphere: 
- The air moves anticlockwise around a low pressure centre; and 
- Clockwise around a high pressure centre. 

In the Southern Hemisphere: 
- The air moves clockwise around a low pressure centre; and 
- Anticlockwise around a high pressure centre.

With regards to this question,

To interpret this chart, we first need to identify the hemisphere. Melbourne is in the Southern Hemisphere, where winds circulate clockwise around low pressure systems and anticlockwise around high pressure systems. The wind indication helps us identify the circulation around the systems shown.

Looking at the contours, we can see that both A and B are low pressure systems. However, the low at A is deeper, as it contains more contour levels towards its centre. As geopotential height decreases towards the centre of a low, the pressure surface is at a lower altitude closer to its centre. Therefore, the pressure surface is lower over A than over B. Consequently, an aircraft maintaining the same flight level will have a higher true altitude over B than over A.

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