I'm pretty sure the answer to this question is choice D.
Answer:
Probability of tractor do not start = 7.67%
Explanation:
Given data:
Probability of not start at red = 6%
Probability of not start at white = 11%
Probability of not start at Blue = 8%
Percentage of tractors produced in red line = 48%
Percentage of tractors produced in white line = 31%
hence Percentage of tractors produced in white line = 1 - 0.48 - 0.31 = 0.21
Probability of tractor do not start 
Probability of tractor do not start = 0.0288 + 0.0231 + 0.0248 = 0.0767
Probability of tractor do not start = 7.67%
Resting heart rate will be decreased, because your heart and cardiovascular system are being worked out, therefore increasing the muscle tissue within the heart and thereby making it stronger, which makes it beat more powerfully and yeah. So Resting heart rate is the correct answer