Step 1: Understanding centralisation. 
  
Centralisation refers to the concentration of decision-making authority at the top levels of the organization. This means that the senior leaders retain control over major decisions, rather than dispersing authority to lower levels. 
Step 2: Analyzing the options. 
  
(A) Retention of decision making authority: Correct. Centralisation is characterized by the retention of decision-making authority at the top of the hierarchy. 
  
(B) Dispersal of decision making authority: Incorrect. This is the definition of decentralisation, not centralisation. 
  
(C) Creating divisions as profit centres: Incorrect. This is related to decentralisation and managing financial responsibilities at the divisional level. 
  
(D) Opening new centres or branches: Incorrect. This is a strategy of expansion, not a definition of centralisation. 
Step 3: Conclusion. 
  
The correct answer is (A) Retention of decision making authority, as centralisation focuses on keeping decision-making power at higher levels in the organization.