Answer:
Option A
Explanation:
Given, initial velocity,
$u=54 km/h=54 \times \frac{5}{18}$m/s
u=15 m/s
Distance of signal from vehicle , d=400 m
acceleration , a= -0.3m/s2
Now, distance covered by vehicle , when it stops is given by $v^{2}=u^{2}+2as$
$0=(0.5)^{2}-2 \times 0.3 \times s \Rightarrow s= \frac{225}{0.6}=375m$
Relative position =400-375=25m