The correct answer is: A. a tasks and the data are related.
Communicational cohesion is a type of cohesion that refers to the way in which the tasks and data in a program are related. In a program with good communicational cohesion, the tasks and data are closely related to each other, and each task has a clear purpose. This makes the program easier to understand and maintain.
Option B is incorrect because it states that the tasks are related, but the data are not. This is not necessarily true. In a program with good communicational cohesion, the tasks and data are both related to each other.
Option C is incorrect because it states that the data are related, but the tasks are not. This is also not necessarily true. In a program with good communicational cohesion, the tasks and data are both related to each other.
Option D is incorrect because it states that the tasks and data are unrelated. This is not true for a program with good communicational cohesion. In a program with good communicational cohesion, the tasks and data are closely related to each other.