Task: Question Answering
Input (English): Problem: the cost of registration at a professional association meeting was $ 50 per person ; a lunch for registrants only was available for an additional $ 22 per person . if the number of registrants who paid for lunch was 10 more than the number who did not , and if receipts for registration and lunch totaled $ 61720 , how many people paid just for registration at the meeting ? 
Options: a ) 700 , b ) 800 , c ) 1,300 , d ) 500 , e ) 1,800
Output (English): d