A. Serbia
B. Somalia
C. Syria
D. Russia
Explanation:
Trans-Siberian Railroad, Russian Transsibirskaya Zheleznodorozhnaya Magistral, (“Trans-Siberian Main Railroad”), the longest single rail system in Russia, stretching from Moscow 5,778 miles (9,198 km) east to Vladivostok or (beyond Vladivostok) 5,867 miles (9,441 km) to the port station of Nakhodka.