The egg because chickens come out of eggs

But what laid the first egg?

Ok you got me

An animal that wasn’t a chicken.

If you consider the creation story as presented in Genesis I would have to say the chicken. Because God created everything already fully formed and then told them to reproduce. It wouldn't make sense for him to make Adam a baby needing to fend for himself. Same with an egg.

Chicken

Well I had eggs before the chicken was done roasting, so there’s that....

I'll get back to you when my order is shipped

Neither. Without the egg, there'd be no chicken, and vice versa. Because if this interdependency, they are one and the same.

The chicken because it’s in the egg

the ovum

chicken and egg. Same time