I think you should change what is single choice & what is multiple choice on your poll.
Like what others have said, sometimes I come up with a bassline straight away, sometimes it can take a while & sometimes it'll start off as onething but get rewritten at a later date as I spend more time with the song. Some basslines are simple, some are complex, it depends what the song needs. Some simple basslines can be a challenge as it could be a simple 3 note sequence, but the stamina to keep it going can be pushed. Some of my complex basslines that I thought would be hard turn out to be easy to play once I get a technique going.
I've always written my own lines, but sometimes another member has said "I've got an idea for a bassline" & I'm happy to play it. When it works, it's nice to see the smile on their face.
The main things that are important to me are "I enjoyed playing that" & "does it fit the song".