Which calculated metric should the analyst create to report on the internal search conversion rate for purchases?

An analyst has the following metrics available for a retail site:

– Revenue

– Orders

– All Visits

– Internal Search Visits

– Internal Searches

– Cart Adds

Which calculated metric should the analyst create to report on the internal search conversion rate for purchases?
A . Internal Searches/Cart Adds
B . Cart Adds/Internal searches
C . Internal Search Visits/Revenue
D . Orders/Internal Search Visits