An accident has taken place at out station and main line is blocked and relief train is to be turned out without medical car. The hooter shall be:
a. 3 long
b. 4 long*
c. 4 long, 1 short
d. 3 long, and 1 short
a. 3 long
b. 4 long*
c. 4 long, 1 short
d. 3 long, and 1 short