Answer:
The answer is the first option. The trailing edge is composed of many filopodia containing tight parallel bundles. These filopodia push trailing edge away from the location it was previously occupying.
Step-by-step explanation:
Cells migrating in tissues exhibit both filopodia and lamellipodia. These thin protrusive extensions are ideal for exploring and penetrating tissue spaces. They are also well suited for intercalating between cells, such as during the migration of leukocytes across endothelial layers.
Therefore the answer is the first option.