Which is the best test to use in this situation?

[sllona]

I have done an experiment (user study) to analyse how the efficiency of using a website influenced by using multiple devices to conduct one task.
The situations that I am testing (i.e. thinking they might affect the efficiency) are:
the transition between :

• Group A: same devices and same operating systems [ e.g. 2 MACs laptop]
• Group B: different devices and same operating systems [e.g. MAC laptop and IOS phone]
• Group C: same devices and different operating systems [e.g. MAC laptop and Windows laptop]
• Group D: different devices and different operating systems [e.g. MAC laptop and Android phone]

My hypothesis is that, execution time used by users within Group :

• A will reflect the highest efficiency (i.e. the lowest amount of time)
• D will reflect the lowest efficiency (i.e. the highest amount of time)
• C will be more efficient than group B

this is the result of the execution time used (i.e. efficiency) by each group:

1. How is statically possible to compare these cases? What's statistical test is best to use?
2. How to make the comparison between the groups for each service (e.g. AliExpress, ebay. ..) and another comparison for the average ?
3. How to interpret the results?

Could you help me with these questions, please?
Regards,
Sara