Among the types of coupling between modules, which is the weakest and gives the highest module independence?

Answer: C. Data coupling

Coupling expresses how much modules depend on each other; the weaker it is, the more independent and desirable the modules. In increasing order of strength, it is classified as data, stamp, control, external, common and content coupling. Data coupling passes only the necessary data as simple arguments. Control coupling passes flags and the like that switch the flow of processing, and common coupling has several modules refer to the same global data (global variables); both make modules depend on each other's internal workings.

• A. Several modules refer to the same global data; this is the strongest coupling after content coupling.
• B. Flags that switch the processing are passed, so the caller depends on the callee's internal workings.
• C. Correct. Only the necessary data are passed as arguments, which is the weakest coupling.