The T-Value for Testing $H _ { 0 } : B _ { i } = 0$

Multiple Choice

The t-value for testing $H _ { 0 } : B _ { i } = 0$
Is calculated using which of the following equations:

A) n - k - 1
B)
$\sum \left( X _ { i } / Y _ { i } \right)$
C)
$B _ { j } / s _ { i }$
D)
$$b _ { i } / s _ { b _ { i } }$$