Which currency to which country ??

This question was asked on Koun Banega Karodpati program.

Question 

Question was picture based.

A photo having the flags of 3 nations was shown.

They were the flags of

South Africa            Russia            Iran 

Currencies of these countries start with which letter of English alphabet ?

  R         D         S           P

Answer 

On the program, only country flags were shown.

I identified the flag of South Africa  !!!

The remaining two, I checked on web.

Even their currencies I didn't know  !!!

South Africa    =    Rand   =  R

Russia   =  Ruble  =   Rub

Iran  =  Rial  =   R

As we can make out, the currencies of all the above countries atart with  English alphabet    "   R   "   !!!

In Iran, they use Toman in daily life.

Iran is planning to change officially to Toman soon.

But at present, it is  Rial   !!!

Correct answer    R   !!!