Suggest two marine processes forming these coastal landforms?

Hydraulic action (1) where the force of the waves hit the cliffs forcing air into cracks (1). • Abrasion (1) where waves pick up stones which hit the cliff (1). • Corrosion/solution (1) where sea water dissolves rocks (1). • Arch is widened by the waves and then the roof collapses (1) stack formed as a result (1). • Stack attacked by wave action (1) worn down over time to form stump (1).