So, as we move on, the next area that shows up is the man's shirt. Place a marker in the white here, too. Remember: shift-click.
Why do we select this area? Because it is the first significant area of visible white.
When you're done, CANCEL Threshold. We're done using it, and don't want to leave our image looking like this.
NOTE: When you're ready to get rid of those pesky little markers, here's what you need to do: make sure you're in the eyedropper tool (or Curves or Threshold), and option-shift-click (alt-shift-click, PC) on each of them. The cursor will look like a little scisssors, and will remove the markers.