In Which Case Is the Confidence Interval for β Narrow

Multiple Choice

In which case is the confidence interval for β narrow? ​

A) When b is large, implying a relatively precise knowledge of the value of β.
B) When s_b is large, implying a relatively precise knowledge of the value of t.
C) When b is small, implying a relatively precise knowledge of the value of β.
D) When n is large, implying a relatively precise knowledge of the value of t.
E) When s_b is small, implying a relatively precise knowledge of the value of β.