Refer to the table which summarizes the results of testing for a certain disease. A test subject is randomly selected and tested for the disease. What is the probability the subject has the disease given that the test result is negative. Round to three decimal places as needed.
Positive Test Negative Test $\square$
Subject has the disease
Subject does not have the disease
Result
87
27
Result
9
312
A. 0.094
B. 0.028
C. 0.221
D. 0.972

Step 1 ：The problem is asking for the probability that a subject has the disease given that the test result is negative. This is a conditional probability problem.

Step 2 ：We can use the formula for conditional probability to solve this problem. The formula is \(P(A|B) = \frac{P(A \cap B)}{P(B)}\). In this case, event A is the subject has the disease and event B is the test result is negative.

Step 3 ：We can find \(P(A \cap B)\) by looking at the number of subjects who have the disease and tested negative, which is 9.

Step 4 ：We can find \(P(B)\) by looking at the total number of subjects who tested negative, which is 321.

Step 5 ：Substitute these values into the formula, we get \(P(A|B) = \frac{9}{321} = 0.028037383177570093\).

Step 6 ：Rounding to three decimal places, the final answer is \(\boxed{0.028}\).