Which of the following sentences uses the word "assumption" correctly?

the assumption kelly was working on ended when school began and she had to spend more time studying
based on the assumption all girls liked him, niles felt sure heidi would say yes when he asked her out.
aidan was afraid the assumption of the exam would be too difficult and that he would fail the class.
a friendly assumption makes it easier to get to know other people in new situations.

Read the quote from zimmermann in the code book. a future government could inherit a technology infrastructure that's optimized for surveillance, where they can watch the movements of their political opposition, every financial transaction, every communication, every bit of e-mail, every phone call. everything could be filtered and scanned and automatically recognized by voice recognition technology and transcribed. it's time for cryptography to step out of the shadows of spies and the military, and step into the sunshine and be embraced by the rest of us. which question does this paragraph answer? why does zimmermann think encryption is important? what kind of encryption did zimmermann invent? how does zimmermann’s encryption work? who made encryption based on zimmermann’s work?