They could either repurpose the old U+20A8 RUPEE SIGN or (less stupid) try to get one of the unallocated Slots U+20B6 to U+20CF following the allocated currency signs.
I'd go with B as you say, because per the article Nepal and Pakistan use the existing symbol for their own currencies.
It will be interesting to see how this shakes out - the spec for Unicode 6.0 is due in September, theoretically giving them time to add it before the release.