1. The 2. workers 3. busy 4. are A. 1243 B. 1234 C. 1423 D. 1432

The correct answer is B. 1234.

The first option, 1243, is incorrect because the word “are” comes after the word “busy”. The second option, C. 1423, is incorrect because the word “busy” comes after the word “workers”. The third option, D. 1432, is incorrect because the word “workers” comes after the word “are”.

The correct order of the words is 1234, which is “The workers are busy”.