What is the correct sequence of the following events in rock tunnelling?

What is the correct sequence of the following events in rock tunnelling?

1. marking tunnel profile
2. loading explosives and blasting
3. checking misfire
4. mucking
5. removing foul gas
6. setting up and drilling
7. guniting

Select the correct answer using the codes given below
Codes ?
A. 1,6,5,3,4,2,7
B. 1,2,6,3,5,4,7
C. 1, 6,2, 5,4, 3, 7
D. 1,6,2,5,3,4,7