A:one thousand, two hundred and six
B:one thousand two hundred and six
C:ten thousand, two hundred and six
D:ten thousand, two hundred, six
十月革命胜利后,苏俄人民响应布尔什维克党“一切为了前线”的号召,发扬拼命精神,忘我劳动。这里的“前线”指的是( )