C/D: WHO makes a topic is a factor in whether you reply or not

For example, let's say Red is a user you like while Blue is kind of a nobody.

Red makes a topic saying "I like pie"
Blue also makes a topic saying "I like pie"

You're more likely to respond to Red while ignoring Blue, even tho the subject of pie doesn't interest you much.

Or is your interest in the subject the sole determinant in whether you respond to a topic?

I'll admit, C. I usually click topics if I'm interested in the subject and ignore ones that don't interest me. But if a user who's posts I enjoy makes a topic that's not really interesting in subject matter, I'll still click to see what they say.