I think the questions that must be ask are:
a.What does “encryption” mean?
d.What are “key distribution problems”?
All the text is based on the concept "encryption" so it is very important to know what it means in order to undestand the rest of the information. If not, you will be missing important facts. In addition, there are a lot of words used that are derived from this one, so you won't be able to undestand them.
Another important concept that gives a lot of information just by knowing it's meaning is "key distribution problems", they could be two or a thousand, it is important to know what they are and what they do.
The other question that seems important is the one of the "public key cryphtography" but this one can be inferred by the context.
Answer:
10- Oxymoron
The words "safety" and "hazard" are right by each other and those are complete opposites so that is an oxymoron.
11- alliteration
The use of the b's at the beginning of a lot of the words is alliteration because it is the repetition of a similar sound at the beginning of the word. The only other one that it could be is consonance because consonance also repeats a sound, but only consonants and it is usually at the end of the word. Even though b is a consonant, I don't think it is consonance because the repetition appears at the beginning of the word.
12- Anaphora
This is anaphora because the word "singing" is being repeated in most of the clauses in order to place emphasis on it.
Answer:
This is not surprising because there are about 100 billion stars in our galaxy.
The answer is C. A theme is the lesson that the author is trying to teach to the reader.