We measure ten units from the latest production lot to measure the length of the product that gives the sample mean to be 17.55 inches, and the sample standard deviation to be 1.0 inch. The 95%, confidence interval for the population mean is:

A

$$17.55 \pm z_{0.05}\frac{1}{\sqrt10}$$

B

$$17.55 \pm t_{9,0.025}\frac{1}{\sqrt10}$$

C

$$17.55 \pm t_{9,0.05}\frac{1}{\sqrt10}$$

D

$$17.55 \pm z_{0.025}\frac{1}{\sqrt10}$$