Step 1: Identify retiring partner's rights.
At retirement, a partner is entitled to:
- Share of profits till date of retirement.
- Share of goodwill.
- Share of accumulated profits and reserves.
- Share of gain/loss on revaluation of assets and liabilities.
Step 2: Analyze given options.
(A) Included.
(B) Included.
(C) Included.
(D) Included.
Step 3: Conclusion.
All four components form the sum due to a retiring partner.
Final Answer: \[ \boxed{\text{(A), (B), (C) and (D)}} \]