Calculate the current exchange rate AUD/GBP, given these two quotes:
AUD/USD 0.5640-50
GBP/USD 1.5850-60
a. AUD/GBP 0.3556-65
b. AUD/GBP 0.3558-62
c. AUD/GBP 0.8945-55
d. AUD/GBP 0.8939-45