Remark
Without being given choices, we can get answers but they may not be listed among your. The important think is to be working in the same units
Convert miles/hour to m/sec

Now just multiply all the numerators together and divide by all the denominators.
Numerators: 2.5 * 1.6 * 1000 = 4000
Denominators: 3600
numerator/denominator = 4000/3600 m/s = 1.111 m/s
Conclusion
Talia is a much faster swimmer than Alina because 1.8 is greater than 1.11. Both numbers are in m/s.
2.5 miles / hour = 1.