They're Not All Equally Likely?

Probability Level 1

If I toss a fair coin 4 times, which of the following is most likely to occur?

Clarification: Each coin toss is independent to one another.

Image Credit: Wikimedia Ipipipourax.

The total number of heads obtained is 0 The total number of heads obtained is 1 The total number of heads obtained is 2 The total number of heads obtained is 3 The total number of heads obtained is 4