oh i didn't know there was a guide, thank you!
actually, our class is doing The Tempest for AOS so i think there's room for a 2nd RT there 
for Mod A i assume we are only expected to do both prescribed texts (1984 + Metropolis), but idk we're only up to Mod B
thank you both for the clarification 
Easy! Thanks for asking! I suggest that you prepare to use one super, super strong ORT and be ready to go to town with it. However, I also suggest that you have a backup ORT to use either in the situation of them asking for two ORTs, or you find that your prepared ORT doesn't respond well to the question and you'll need the support of another ORT.
As I said, since 2004, only ONCE have they asked for two. I'm guessing that they haven't done it again either because students performed poorly or because they found it to be unnecessary. Key words: "I'm guessing."

Oops I meant "use 1 RELATED text as well" !!! My late night practise yesterday must have resulted in my confusion of speech
For Module A, ORTs are not common. Let's have a look at one of the 2015 Mod A questions:
Does the treatment of social manipulation in Nineteen Eighty-Four and Metropolis reveal the texts’ similarities or reinforce their distinctive qualities?
In your response, make detailed reference to your prescribed texts. The question specifically requests that you make a comparative study of the two texts explicitly. I can see that mentioning another text for the purpose of strengthening an argument could be worthwhile. However, I can't see how actually entering a full textual analysis could be of benefit to this module.
Have you been told differently?