Read the excerpt from the foreword to wheels of change.

mary lewanika, a student living in rural zambia, is having a profound experience in being empowered to steer her own course. at 17, in 2009, lewanika was the very first student to receive a world bicycle relief bike. that day she said she felt safer already on the long, sometimes dangerous path to and from school. this is particularly important for lewanika, as she wants to stay in school and graduate from college to become a doctor.

what type of evidence does the author use to support her argument?

expert testimony
a statistic
an example
scientific analysis