This is a 1998 Honda Accord LX.

I took out the nut connecting the control arm to the subframe. However, I am unable to remove the bolt that is still holding the control arm to the subframe.

I've tried various methods of removing the bolt such as hammering, and using WD-40, etc.

Any idea on how to remove this bolt?

I've included a picture (URL as the full image is way too big). The bolt is the lower one:
Picture

 

try applying pressure to the outside of the bolt and the ratcheting it out. sometimes that helps.