P46 form: Which box to tick?

I've a received P46 form from my employer, but I'm at a loss as to which of the 3 boxes (A, B, C) to tick:

A) This is my first job since last 6 April and I have not been receiving taxable Jobseeker's Allowance or taxable Incapacity Benefit or a state or occupational pension
B) This is now my only job, but since last 6 April I have had another job, or have received taxable Jobseeker's Allowance or Incapacity Benefit. I do not receive a state or occupational pension.
C) I have another job or receive a state or occupational pension.

I have never worked in the UK before (was self-employed in the US prior) and none of the options mention this nor does any supporting information I can find online. I'm guessing I tick option A??? I don't like being taxed at the emergency rate. Can someone help me?

Kind regards,
Elise

I've a received P46 form from my employer, but I'm at a loss as to which of the 3 boxes (A, B, C) to tick:

A) This is my first job since last 6 April and I have not been receiving taxable Jobseeker's Allowance or taxable Incapacity Benefit or a state or occupational pension
B) This is now my only job, but since last 6 April I have had another job, or have received taxable Jobseeker's Allowance or Incapacity Benefit. I do not receive a state or occupational pension.
C) I have another job or receive a state or occupational pension.

I have never worked in the UK before (was self-employed in the US prior) and none of the options mention this nor does any supporting information I can find online. I'm guessing I tick option A??? I don't like being taxed at the emergency rate. Can someone help me?

Kind regards,
Elise

You can always try CAB (Citizen's Advice Bureau) for info. My dad used to work in accounts - he's retired now - I'll ask him and get back to you.

If you stopped doing your self-employment once you arrived here, you want A. 

If you continued your self-employment after you moved here, you want C.  If you continued, you also should sign up to pay UK self-employed national insurance tax.  www.hmrc.gov.uk is the place to start.

It is quite a common occurance to be paid after your move for work done prior to your move.  If you completed all your self-employment work before you moved here, but some customers paid you for that work after you arrived here:
(a) it is UK tax-free
(b) it does not count as UK self-employment
(c) you owe US and state tax on that money instead.

Thank you! Just wanted to get a definitive answer. I feel much better now.   

Great you got your answer. Sorry I couldn't help out sooner.