Answer:
According to Lorentz transformation, the time observed of by objects moving in different reference frames are related to their velocity of motion and the speed of light
The time measured by Sarah who is located at the source of the signal and the center of the explosion is different from the time measured by Adam who is moving relative to Sarah and observes the signals moving at different speeds and therefore observes the buildings blow up not immediately but at different times
Step-by-step explanation:
The time and space dilation equations are given as follows;


Where;
Δt' = The time measured by Adam
Δt = The time measured by Sarah
L' = The distance measured by Adam
L= The distance measured by Sarah
v = The velocity at which Adam is moving
Let 'u' represent the speed of the signals
Given that Adam is traveling in between the two clock towers such that one signal is moving in the opposite direction towards him while the other signal moves in the his direction, by relativistic velocity addition, we have;
The velocity with which Adam observes the signal coming towards him, v' is given as follows;
v'' = (v + u)/(1 + v·u/c²)
∴ v'' > v
For the signal moving in the direction of Adam, we have;
v''' = (v - u)/(1 - v·u/c²)
v''' < v
Therefore, we have;
The time it takes the light to reach Adam from the furthest Tower which he passes as he is flies past Sarah in the middle, Δt'' is given as follows;

For the closer tower which Adam approaches, we have;

Given that v'' > v''', therefore Δt'' < Δt''' and the time the light from the furthest building is seen first by Adam before the light from the closer building.