D. <span>use clear, short paragraphs.</span>
Answer:
I think sentence 3 bc it doesn't really make any sense Ik it's explaining it but it doesnt connect with the whole story as much I think it has to have more details
Answer: PKI certificates
Explanation: PKI is known as the public key infrastructure which is commonly used for the encryption of the data and also for the data signing. They have the ability to assign the keys pair.
PKI certificates are in the form of strings of alpha-numeric running for a mathematical functions. They use the third party protocols for the execution and they are widely accepted by the authoritative identity.
1. ms-dos 1981
2. windows 2.0 1987
3. windows xp 2001
4. mac os 2001
5. windows 7 2009