What is the standard length and anchoring method for a precast concrete wheel stop in a commercial asphalt parking stall?

1. 4-foot length anchored with liquid silicone caulk along the bottom.
2. 5-foot length anchored with 2-inch plastic masonry screw anchors.
3. 6-foot length anchored with two #4 or #5 steel rebar pins driven into asphalt.
4. 8-foot length anchored by pouring a continuous 6-inch concrete curb footing. only