Explanation/Reference:
Explanation: The relationship between Employee and e-mail is poorly implemented here.
There is low cohesion.
Note:
Low cohesion is associated with undesirable traits such as being difficult to maintain, difficult to test,
difficult to reuse, and even difficult to understand.
Cohesion is decreased if:
The functionalities embedded in a class, accessed through its methods, have little in common. Methods
carry out many varied activities, often using coarsely-grained or unrelated sets of data. Disadvantages of
low cohesion (or"weak cohesion") are:
Increased difficulty in understanding modules.
Increased difficulty in maintaining a system, because logical changes in the domain affect multiple
modules, and because changes in one module require changes in related modules. Increased difficulty in
reusing a module because most applications won't need the random set of operations provided by a
module. Reference:Cohesion (computer science)