URL best practices

I would like to ask about the structure of the website. Let's do it on the example of an SEO company. It turns out that the greatest traffic is on local phrases in specific cities - New York, Los Angeles, Chicago.

What's best method?
a)
companyname.com/seo/ (long article about SEO).
companyname.com/seo-services/ (long article about SEO services)
companyname.com/seo-los-angeles
companyname.com/seo-new-york
companyname.com/seo-chicago

b)
companyname.com/seo/ (long article about SEO)
companyname.com/seo/services (long article about SEO services)
companyname.com/seo/los-angeles
companyname.com/seo/new-york
companyname.com/seo/chicago

Maczupikczu said:

a)
companyname.com/seo/ (long article about SEO).
companyname.com/seo-services/ (long article about SEO services)
companyname.com/seo-los-angeles
companyname.com/seo-new-york
companyname.com/seo-chicago

Click to expand...

This has worked for me.

RoiBox said:

This has worked for me.

Click to expand...

Thanks! I've noticed that most companies use this, the only company that tries to do it differently is WebFX. Except that they have the most traffic (1.1 million).

And that's the only reason why the "a" method gives me any doubts.