Answer:
I think this is mathematics not history...
Answer:
The correct answer of the given question above would be the first option. It is important to know a currency's exchange rate when you are planning for the expenses for an overseas trip. When you are overseas, the money you will be using should be exchanged for the currency depending on where you travel and currency changes from time to time and differs from country to country so it is necessary to know the rate beforehand. Hope this answer helps.
Income? i’m not sure what time period you are talking about but if it’s now in 2020 it would be by income
