The __________, which stretch over 36,000 square miles, cover more surface area than the __________, which stretch over 1,500 miles.
A. Pamirs . . . Tian Shan
B. Tian Shan . . . Pamirs
C. Eurasian Steppe . . . Pamirs
D. Eurasian Steppe . . . Tian Shan