The mother of a 12-year-old has been referred to an orthopedist’s office after she noted that her child was walking on the tips of the toes. The physician diagnosed the child with a short Achill

The mother of a 12-year-old has been referred to an orthopedist’s office after she noted that her child was walking on the tips of the toes. The physician diagnosed the child with a short Achilles tendon, and surgery was performed to correct this condition. A few months later, the child began to vomit every morning and complained of frequent headaches. The mother returned to the pediatrician’s office, and a head CT scan was ordered. The child was diagnosed with a brain tumor.
Most childhood cancers originate from the:
a) Oncogenes
b) Blast cells
c) Prenatal exposure
d) Mesodermal germ layer