Which of the following statement(s) is/are true with respect to Phillips Curve ?
1. It shows the trade-off between unemployment and inflation
2. The downward sloping curve of Pliillips Curve is generally held to be valid only in the short run
3. In the long run, Phillips Curve is usually thought to be horizontal at the non-accelerating inflation rate of unemployment (NAIRU)
Select the correct answer using the code given below :

Options

A. 1 only
B. 2 and 3 only
C. 1 and 2 only
D. 1, 2 and 3