Step 1: National Assembly Building, Dhaka (Louis Kahn).
- Louis Kahn designed the National Assembly (Capitol Complex) with a strong central geometric core. - The assembly hall is centrally located, with surrounding functions emanating from it. - This exemplifies a centralized organization. \[P \Rightarrow 1\]
Step 2: Secretariat Building, UNESCO HQ, Paris (Marcel Breuer).
- The Secretariat is a long, linear slab building. - Its design and layout feature a linear organization, with spaces arranged along a central axis. \[Q \Rightarrow 4\]
Step 3: Fatehpur Sikri Palace Complex (Mughal architecture).
- The palace complex is not organized around a central axis; instead, it expands by adding courtyards, halls, and residences around existing structures. - This demonstrates a clustered organization, where spaces are grouped closely without strict symmetry. \[R \Rightarrow 2\]
Step 4: Shodhan House, Ahmedabad (Le Corbusier).
- The house is structured around a robust orthogonal framework. - Its use of repeating grid-like planning elements clearly illustrates a grid organization. \[S \Rightarrow 5\]
Step 5: Match with given options.
The correct sequence is: \[P-1, \; Q-4, \; R-2, \; S-5\] Option (A) corresponds to this sequence.
Final Answer: \[\boxed{\text{(A) P-1, Q-4, R-2, S-5}}\]