Using the Hat Matrix Elements H_i to Determine Influential Points

Multiple Choice

Using the hat matrix elements h_i to determine influential points in a multiple regression model with k independent variable and n observations,X_i is an influential point if

A) h_i > n(k + 1) /2.
B) h_i > 2(k + 1) /n.
C) h_i < n(k + 1) /2.
D) h_i < 2(k + 1) /n.