Partner’s citizenship certificate reference number

[Farrukh_2000]

Hello everyone
My wife is applying for British citizen ship after I had my citizenship ceremony
In her application it’s asking for Partner’s citizenship certificate reference number?
On my citizenship certificate there are two at the bottom
A. Certificate no.( Which is 7 digit number)
B. Reference no.(which is 9 digits number)
Which one should we put in this question A or B?
Thanks

[alterhase58]

B. Reference no