What is a slurry seal as defined in California highway specifications?

1. A thin layer of clear polyurethane resin sprayed onto new concrete decks. only
2. A mixture of molten rubber and sand squeegeed over individual cracks.
3. A mixture of graded aggregate, emulsified asphalt, water, and mineral filler.
4. A single coat of waterborne acrylic paint sprinkled with glass beads.