Explain what is different about how Silicon Valley companies have built their networks and what it means for the general public and law enforcement?

Explanation:

What happens in this case is that Silicon Valley companies did not build surveillance as a structural basis for their communication products, as it does with technology products, such as cell phones, that use encrypted technology that makes surveillance difficult.

So for the public it means security in terms of leaking confidential information, and for law enforcement it consists of a difficulty in using wiretaps for example, in a specific surveillance situation.

i think the answer is a or d