Bentley is developing a model to predict whether a customer will default on a loan or not. Customers who default are indicated as 1 in his model output. Customers who do not default are indicated as 0. He hopes to evaluate his model by looking at of all customers that default, what proportion his model is able to capture. The appropriate evaluation metric to answer this question is _______.
a) F1-score
b) recall
c) accuracy
d) precision