Refer to the Following Paragraph to Answer the Questions Below

Multiple Choice

Refer to the following paragraph to answer the questions below.
The infant mortality rate (number of infants who die in their first year per 1,000 births) has a mean for the OECD (most advanced industrial countries) of 8 with a standard deviation of 1.
-The infant mortality rate in the U.S. is 9 infant deaths per 1,000 births. The rate for Ireland, Singapore, Hong Kong, Netherlands, France, Canada, Germany, and Switzerland are all the same. Their rate is 2 z-scores below that of the U.S. What is their rate?

A) 6
B) 6.5
C) 7
D) 7.5
E) 8