Final answer:
The statement B is true: Rosa's time is closer to 42.79 seconds than 42.78 seconds.
Step-by-step explanation:
In order to determine which time is greater, we need to compare the numbers after the decimal point. In this case, Ian's time is 0.839 seconds and Rosa's time is 0.782 seconds.
When rounded to the nearest hundredth of a second, Ian's time becomes 42.84 seconds and Rosa's time becomes 42.78 seconds. Since 42.78 is closer to 42.79 than 42.78, Rosa's time is closer to 42.79 seconds.