Answer: B. (Leah did not have to provide collateral.)
First of all, try to understand the questions then try to make a pair of linear equations. After that make the coefficients of x or y equal in both RFD equations by multiplying them by suitable values then add or subtract them ,in such a way which will terminate any one of the variables. Then find the value of left variable. After that just put the value you have found just now In any of the equations and you'll really get the value of the second variable too.