Which of the following is an example of triangular arbitrage initiation?
a. Buying Singapore dollars from a bank (quoted at $0.55) that has quoted the South African rand/Singapore dollar exchange rate at ZAR3.00 when the spot rate for the South African rand is $0.20.
b. Buying a currency at one bank's ask and selling at another bank's bid, which is higher than the former bank's ask.
c. Buying Singapore dollars from a bank (quoted at $0.55) that has quoted the South African rand (ZAR)/Singapore dollar (S$) exchange rate at ZAR2.50 when the spot rate for the South African rand is $0.20.
d. Converting funds to a foreign currency and investing the funds overseas.