In a key management lifecycle, what is your opinion on how long a key should be valid? Who should be responsible for key, user or the organisation?

When designers make compromises during the engineering design process the result is often what?

Ihave an iphone 8plus should i get another phone like samsung note 9 or s9 ? ?

Linux is distributed under gnu gpl. why is this important? a. it ensures that only torvalds can profit from the sale of linux b. it prevents unknowledgeable users from downloading programs they don't know how to operate. c. it provides protection for the developers who created linux. d. it states that anyone can copy, modify, and share the program if changes are made public.