Question: One night, Mrs. Riley, an elderly woman, was walking along a dark London street. She was carrying her handbag in one hand and a plastic carrier bag in the other. There was nobody else in the street except two youths. They were standing in a dark shop doorway. One of them was very tall with fail hair, the other was short and fat with a beard. The youths waited for a few moments, and then ran quickly and quietly towards Mrs. Riley. The tall youth held her from behind while the other youth tried to seize her handbag. Suddenly, Mrs. Riley threw the tall youth over her shoulder. He crashed into the other youth and they both landed on the ground. Without speaking, Mrs. Riley struck both of them on the head with her handbag and walked calmly away. The two surprised youths were still sitting on the ground when Mrs. Riley crossed the street towards a door with a lighted sign above it. Mrs. Riley paused, turned round, smiled at the youths and walked into the South West London Judo Club. The two youths stood in a dark shop doorway because _ . A) they had nothing to do B) they were homeless C) they meant to rob somebody D) they were guarding the shop
Answer:
C