Answer:
option d. end capping
Explanation:
The ABP or actin binding proteins are attached with actin. The actin filaments are attached with ABP. The actin binding proteins provide large number of monomers of actin for polymerization. The ABP also help in new filament assembly. The ABP function in promoting the process of elongation. The ABP allows filament severing/depolymerization.
The end is attached with cap having the pointed or barbed ends. The barbed end gets attached with capping proteins (CP) thus blocking polymerization. So, ABP are not involved in end capping. Thus, option d is incorrect.