Correct Answer:
C. 1955
The correct answer is 1955. Orient Airways, which was the first airline of Pakistan, was nationalized and merged with the government's proposed airline to form Pakistan International Airlines (PIA) in 1955. This marked the official establishment of Pakistan's national flag carrier.
- 1951, 1953, and 1961 are incorrect years for this specific transition and formation of PIA.
The creation of PIA was a significant development for Pakistan's aviation sector.