The average heights of a random sample of 35 people from a specific city is 1.80 meter. It is known that the heights of the population are random variables that follow a normal distribution with a known variance of 0.20 meter. What table critical value would you use to determine the two-tailed 95% CI for the population mean?

a.) t= 1.699

b.) z=1.96

c.) z=1.645

d.) t=1.684