Answer: The disposition option appropriate for this situation is "Rethink"
Explanation: Disposition options in task achievement refers to the option or decision taken in order to maximise efficiency. Apart from the rethink option, there are also the options to (a)keep, (b)combine and (c)eliminate. Each option is specific for different situations.
In a scenario where three people are performing the same tasks using different methods and having varying outputs, it can be inferred that the task is not been done efficiently at least by two of the three people. It is therefore imperative to rethink the activity and the approaches in order to improve efficiency.
Explanation:

<em><u>Bitcoin is a digital currency which operates free of any central control or the oversight of banks or governments. Instead it relies on peer-to-peer software and cryptography. A public ledger records all bitcoin transactions and copies are held on servers around the world</u></em>
If I was u I would go with A
Hope this helps:)