Which organizations should be involved in commmunications planning?

The answer is: All stakeholders

communication planning is a set of standard that determine how a company would reveal various type of information to the people who are relevant to the company. In the creation process, all stakeholders should be involved and make sure that the method implemented by the company is acceptable/suitable to their condition.

All stakeholders

A communication plan is a policy-driven method of supplying stakeholders with message. The plan formally determines who should be provided with a particular message, when that message should be passed and what communication channels will be applied to pass the knowledge. An efficient communications administration plan predicts what knowledge will require to be passed to particular viewers segments.