Can an MA lead to a PhD or would only a MSc do that?

Question is as it is in the title.

Do you have to do a MSc to do a PhD? I'm interested in studying Sociology. Not 100% sure whether I will do a PhD but just in case.

Is a MA less attractive than an MSc for future sponsorship for a PhD?

If it's in a relevant subject then yes, of course.

Thank you.

To be honest I struggle to see what exactly is the difference?

Because I did BSc Sociology and was told that BSc and MSc's are superior to BA's as BA's are supposedly more arty and less scientific. It even says this online.

But having a look at courses you can choose either MSc or BSc and do either quantitative or qualitative research depending on your choice - so the label does't seem to indicate anything?