be quick please

The following are two estimates for the population mean (mu): muy-hat = (X1 + 2X2) / 2 and mu2-hat = (X1 + 4X2) / 4 Where X, and X2 are observations of a random sample from a population X with mean u and variance o2. Which of the following statements is true? O a. mu2-hat is a biased estimator, and the bias is 0.25 mu. O b. mu2-hat is a better estimator using the bias. O c. mu1-hat is a biased estimator, and the bias is 0.5 mu. O d. All of the other statements are True