How Do I Code My Robots.txt File To Disallow Subdomians?

Is it Disallow: /apple.domain.com or Disallow: /apple/

[Christyl Stevens]

If I have the following subdomains on my site then what would my robots.txt file look like and where would I put it to exclude ALL of my subdomains from being indexed?

[apple.domain.com...]

[banana.domain.com...]

[orange.domain.com...]

1.) Would I place the following code

User-agent: *
Disallow: /

In the root directory of my subdomains?

Just like the following since they are treated as separate domains?

[apple.domain.com...]

[banana.domain.com...]

[orange.domain.com...]

2.) Or would I simply place this code in my root directory of my domain, like this?

[domain.com...]

User-agent: *
Disallow: /apple.domain.com
Disallow: /banana.domain.com
Disallow: /orange.domain.com

3.) Or would I simply place this code in my root directory of my domain, like this?

[domain.com...]

User-agent: *
Disallow: /apple/
Disallow: /banana/
Disallow: /orange/

TIA

[mbauser2]

#1