According to F. W. Riggs, the trends in comparative public administration are:
1. Normative to Empirical
2. Ideographic to Nomothetic
3. Empirical to Normative
4. Ecological to Non-ecological
5. Non-ecological to Ecological
Select the correct option:

A. 1, 2 and 4

B. 2, 3 and 5

C. 2, 3 and 4

D. 1, 2 and 5

Answer: Option D