I have a question about currency conversion, in the guidence of tier 1, it states we need to covert according to www.oanda.com, using "the closing spot exchange rate which appears on Oanda".
What is "the closing spot exchange rate"? would someone kindly explain it?
I go to the homepage of oanda, and choose the Fxconventer, concerning the rate, there are several options to choose, such as "interbank rate, typical credit card rate, typical cash rate, interbank rate+1%, ……"
Which option should i choose, is that correct if i choose the "interbank rate" which is on the top?
Really appreciate for any guidence!
Many thanks in advance!

Best regards