Answer:
b. an e-mail
Explanation:
Based on the scenario being described within the question it can be said that the best electronic communication tool in this scenario would be an e-mail. Using e-mails you would be able to send detailed communication messages to all of the individuals that need to read that message in one e-mail. Thus allowing for fast and clear communication between all relevant parties. Both podcasts and Wiki's are used for providing information to clients, or the target audience but not for sharing info within the company.