I dont need work shown just the right answer please

Part A.)

Suppose there are two SRSs from two different populations and the samples are independent. You measure the same variable from both samples. Assume both populations of the values of these variables are normally distributed but the means and standard deviations are unknown. What method do we use in comparing the two means?

A.) Matched Pairs Procedure

B.) Z Procedures

C.) Least Squares Regression Line

D.) 2 sample test

E.) T-Test

Part B.

A political analyst wanted to find out if younger adults were becoming more conservative. He decided to see if the mean age of registered Republicans was lower than registered Democrats. She selected an SRS of 128 registered Republicans and determined the mean age to be 39 years with a standard deviation of 8 years. She also selected an SRS of 200 Democrats and determined the mean age to be 40 years with a standard deviation of 10 years. Let₁and₂represent the mean ages of the populations of all registered Republicans and Democrats. Using the above data, construct a 90% confidence interval for₁-₂.

A.) (-2,0)

B.) (-2.66, 0.66)

C.) (-2.98, 0.98)

D.) (-1.62, 3.62)

E.) (0,2)