It was actually B
You have plenty of time to plan and organize you thoughts
While it might have grown over time and helped us communicate, it also isn't always 100% reliable. And, technology isn't always seen as the safest either, there is no guarantee your information will be safe and secure with technology.
A subordinating conjunction introduces a dependent clause in a complex sentence.
Here is an example:
I checked my emails when I arrived home.
The clause <em>I checked my emails </em>is independent, and <em>when I arrived home </em>is dependent, and it starts with a subordinating conjunction <em>when.</em>
