I am hesitant to provide a definite answer since I'm not completely certain, but it's clear you can discard options C and D right away since the rate of change cannot be negative. Between options A and B, I would lean towards option B. I would have asked you to consider me the brainliest if I were correct, but I suspect this is for the IA4, where you're unable to check your grade... haha. Apologies, but I hope this assists you in some way!
Answer:
(C) They have the same coefficient of variation
Step-by-step explanation:
The coefficient of variation (CV) is calculated using the formula:

Where
represents standard deviation and
represents the mean.
Bob's average weight is 200 pounds with a standard deviation of 16 pounds
This indicates that
.
Thus, his coefficient of variation is

Mary's average weight is 125 pounds, with a standard deviation of 10 pounds.
This implies 
Therefore, her coefficient of variation is

Since both have the same coefficient of variation, the accurate response is.
(C) They have the same coefficient of variation
To find out the number of days, we should create equations based on the values provided. The total distance Kayla aims to travel combines both her running distance and her biking distance.
200 miles = (6 miles/day)x + (10 miles/day)y
where x signifies the days she spent running and y represents the days bike riding.
If the minimum biking days are set to be 15, indicated by y = 15, we have:
200 miles = (6 miles/day)x + (10 miles/day)(15 days)
Solving for x gives:
200 = 6x + 150
50 = 6x
x = 8.3333 days
Total days = 15 days biking + 8.3333 days running = 23.3333 days, approximately making it 24 days.