A software development team found that dependencies between some modules in a project were inevitable. These dependencies resulted in delay in software deliveries, because some teams had to wait, as the module on which their module depended was not ready. Test Driven Development $($TDD$)$ solved this problem by enabling teams to work in parallel, even with modules which were highly dependent on each other. Which of the following principles of TDD could make this phenomenon possible?

It helps to decipher the code

It encourages loosely$-$coupled design

It involves extensive use of mocking

It improves system complexity