Under the Traditional Approach to Children as Witnesses

Under the traditional approach to children as witnesses:

A) Children 10 years of age or older are presumptively competent to testify at trial.
B) Children under the age of 10 have to be found competent following voir dire by the judge.
C) Children under the age of 10 were incompetent to testify at trial.
D) Both a and b are correct.