Yesterday I did n't walk or otherwise exercise . Today , I was hoping to make up for it by walking 6 km . I think I did about that distance , but it 's hard to tell from Google maps .

Question: Why is the person attempting to make up for not exercising on the day prior ?
Answer: None of the above choices .They are required to walk to work as they can not afford to take a taxi and they missed the day beforeThey are fulfilling a requirement for an online gym class and must exercise a given number of hoursThey are committed to improving their physical fitness and are trying to set a quota for themselves