Inquiry about filling a form to immigrate to Quebec

Hi, all

I am filling a form of 'Application for Selection Certificate' for the immigration to Quebec.

Regarding Section 8.1 on the form, I have a question.
The section is...

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8.1 Are any of the diplomas entered under Question 8 Quebec diplomas or their equivant and found among these choices:

1) Quebec diploma
2) Canadian diploma
3) Diploma or training recognized as equivalent by a Quebec regulatory body (except medical degree)
4) Foreign diploma covered by a mutual recognition agreement (ARM)
5) Other
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I have achieved a Master and Bachelor degree of Mechanical Engineering from South Korea and have six years working experiences as a Mechanical engineer there.

But, with the question, I am confused which one I should check. I guess No.1, 2 and 4 are not for me and I seem to have to choose one of the rest, No.3 and 5. Which one is for me? And if I have to check No.5, what should I write for 'Other'?

One more question...

I found the explanation like below from an immigration guide on the official website...

'If you plan to practise a regulated trade or profession in Quebec and you have obtained recognition of the equivalence of your diploma or training from the relevant regulatory body, you must provide proof'

If I get PR in Quebec, I would like to keep my work, a mechanical engineer, there. Can you show me some detailed explanation and/or examples what proof I should provide?

Please share your ideas
Thanks
Have a nice day!

ps. can you recommand me which city is suitable for a mechanical engineer to get a job in Quebec?