A
题意：关于他们住的房间，哪句话是正确的?
A.在一条狭窄的街道上。
B.又小又脏。
C.它在一楼。
D.墙壁和天花板是白色的。
根据倒数第三、四段：
The Dodger led Oliver to a narrow smelly street, and into a house. They climbed the stairs and went into a room at the top.
Oliver looked around. They were in a large room. The walls and ceiling were black with age and dirt.
神偷把奥利弗领到一条窄窄的臭街上，进了一所房子。他们爬上楼梯，走进顶层的一个房间。奥利弗环顾四周。他们在一个大房间里。墙壁和天花板都因年代久远和肮脏而变黑了。
可知房子在一条狭窄的街道上，是大房间，在顶楼，墙壁和天花板是黑色的，
只有A选项说法正确，故选A。