Multi-choice problem: Choose from the options at the end, and answer how do you do this: How do you know when to flip a pancake?

Options:
[a]. Watch the top of the pancake for bubbles. When there are a lot of bubbles and the batter is still a little bit wet-looking, flip the pancake.;
[b]. Watch the top of the pancake for bubbles. When there are just a few bubbles and the batter is still very wet-looking, flip the pancake.;
[a].