Answer:
The correct answer is the last option, that is, 
Step-by-step explanation:
We have been given that the first runner has $112 in savings, received a $45 gift from a friend, and will save $25 each month. Therefore, amount of money in the account of first running after m months will be: 
We have been given that the second runner has $50 in savings and will save $60 each month. Therefore, amount of money in the account of second running after m months will be: 
In order for amount of money to be equal in accounts of both the runners, we set up:

Upon rewriting the left hand side using commutative law, we get:

Therefore, we can see that the last option is the correct answer.