According to the Big Mac Index, the implied PPP exchange rate is Mexican Peso 8.58/$1 but the actual exchange rate is Peso 11.80/$1. Thus, at current exchange rates the peso appears to be ________ by ________.

a) undervalued; approximately 21%

b) overvalued; approximately 27%

c) undervalued; approximately 27%

d) overvalued; approximately 21%