The Confidence Interval for a Single Coefficient in a Multiple $R ^ { 2 }$

Short Answer

The confidence interval for a single coefficient in a multiple regression a. makes little sense because the population parameter is unknown.
b. should not be computed because there are other coefficients present in the model.
c. contains information from a large number of hypothesis tests.
d. should only be calculated if the regression $R ^ { 2 }$ is identical to the adjusted $R ^ { 2 }$ .