How to choose primary key to bind to source code properly

Question

Let's suppose that I have a basic role table

CREATE TABLE IF NOT EXISTS myapp.role (
  id INTEGER PRIMARY KEY,
  name TEXT NOT NULL
);

In my application, I want to restrict somes part of code depending of role. I think about differents solutions but I am not sure what is the best (or if there is a better one).

A) I use an integer as primary key. In my application, i have a enum that is corresponding.

enum Role {
    Admin = 1,
    Moderator = 2,
    Member = 3,
  }

I use this to insert my seed data, and use this in code to check if my user has the right role.

B) I use a varchar primary key. In my application i have a union type corresponding.

type Role = 'ADMIN' | 'MODERATOR' | 'MEMBER';

C) I have a usual serial primary key, and an "identifier" column, then I need to cache or get the database state, and filter by identifier on my cached roles.

D) I don't know.