问题如下：
Using the properties of firms that have already fallen into default/non-default groups to categorize a new observation by how closely it resembles the members already in each of the groups is referred to as:
选项：
A. linear discriminant analysis.
B. the k-nearest neighbor approach.
C. support vector machines.
D. None of the above.
解释：
The K-nearest neighbor is a nonparametric discriminant technique that uses the properties of firms that already have fallen into the categories of interest, and it categorizes a new entrant by how close it resembles the members already in each of the groups.
为什么不是选项C呢？