Final answer:
To express 10:25 in its lowest form, divide both numbers by their greatest common factor (GCF). The GCF of 10 and 25 is 5, so the lowest form is 2:5. Hence the correct answer is option B
Step-by-step explanation:
To express 10:25 in its lowest form, we need to find the greatest common factor (GCF) of 10 and 25, and then divide both numbers by that factor. The GCF of 10 and 25 is 5. So, we can divide both numbers by 5 to get the lowest form. Therefore, the answer is 2:5, which is option B.