During subsonic, adiabatic flow of gases in pipes with friction, the flow properties go through particular mode of changes. Match List I (Flow properties) with List II (Mode of changes) and select the correct answer:
List I
A. Pressure
B. Density
C. Temperature
D. Velocity
List II
1. Increase in flow direction
2. Decreases with flow direction
A B C D
a. 1 1 2 2
b. 2 2 2 1
c. 2 2 1 2
d. 2 1 1 2