I agree with the person above - the complete subject of this sentence is D. a group of men.
The Answer is LOTO. LOTO stands for Lock out/Tag out. When preforming maintenance or repair on machinery it is important to use LOTO or Lock out/Tag out to insure that no one uses the machinery while it is under repair/maintenance. This is important because using a machine while under repair or maintenance could result in serious injury or even death.
Answer:
It is a pronoun
Explanation:
A pronoun is taking the place of a noun. Since you could replace a noun with it, like instead of "the book didnt move" it would be "it didnt move". While this is much less specific, it still counts as a pronoun.
I think number 2 that is what I believe it makes a lot of sense
1597_____________________