Indirect disposal of commercial property

I am asking on behalf of BVI Co. A, which has requested a UTR for Corporation Tax filing in 2024. BVI Co. A wholly owns BVI Co. B for over 10 years, and B is dormant since incorporation. B bought one UK commercial property in 2016, paid stamp duty and earned rental income solely throughout the years. No other acquisitions / asset / business in B after 2016 acquisition.
In 2024, A sold entire shares of B to third parties. B is property rich asset because it owned one UK commercial property only. For the calculation of A's gain/loss on indirect disposal of UK land, as B bought the property but A sold the shares of B, are we going to use the property value or the share value as sales proceeds? Could we use total acquisition cost of property in 2016 when we calculate the gain/loss on indirect disposal of UK land?
I am quite confused with the below link. Thank you very much.
https://www.gov.uk/guidance/capital-gains-tax-for-non-residents-calculating-taxable-gain-or-loss?gad_source=1&gclid=CjwKCAjw68K4BhAuEiwAylp3kqn4_C3wFJra3tHK1HjbRGW7gboju9fatuezeXKg_dLAgbzd6q8ikRoCPPgQAvD_BwE

Hi,
This forum is for general queries only and is intended to help you self-serve. 
HMRC cannot give tax planning advice which is the category your question falls into.
Guidance is available at Businesses and as already quoted by you at:
Work out your tax if you're a non-resident selling UK property or land 
You will need to determine what action you need to take after consulting the guidance or engaging a financial advisor/accountant to assist.
Please refrain from posting the same question multiple times on this Forum and await the answer to the first question posed  
Thank you.