In 1952, a smog outbreak blanketed the capital city of England, killing as many as 12,000 people. Fog combined with many smoke from many sources to produce this disaster. Which of these was the LEAST contributor to the smoke that caused the smog? A) car exhaust B) subway trains C) home chimneys D) factory smokestacks

B) subway trains

Explanation:

On December 5, 1952, during a bitter winter, London encountered a strange mist that seemed to increase in size and intensity more and more. This fog began to take over the city and take on a frightening color, especially when it was mixed with smoke and soot produced.

factory smokestacks, home chimneys and car exhaust, which made the fog a huge threat to the air and the breath of Londoners. The fog was so devastating that it killed up to 12,000 people.