In a plan to stop the erosion of East Coast beaches, the Army Corps of Engineers proposed building parallel to shore a breakwater of rocks that would rise six feet above the waterline and act as a buffer, so that it absorbs the energy of crashing waves and protecting the beaches.

• Aact as a buffer, so that it absorbs  
• Bact like a buffer so as to absorb  
• Cact as a buffer, absorbing  
• Dacting as a buffer, absorbing  
• Eacting like a buffer, absorb