How do I make the graphic choices larger?

I have a question that involves selecting a smiley face that reflects their attitude toward an object (in this image I only have one of the faces for testing it out, but it'll actually be a spectrum). However, the icons are too small, and when I try to increase the size of the image it actually gets smaller! Basically I want them to be as large as the gray area around the smiles. The 9 choices need to be horizontal. Any ideas? Thanks!