If you have sent ITR 1 and ITR V (acknowledgement) along with the computation then you have provided everything you can.....They need to clarify what are they asking for...
As ITR 1 is called Sahaj and ITR - 4 is called Sugam
When they say ITR Saral form...AFAIK it is an Old form dated back in 2010 and it does not exist anymore...