Which correction should be made to sentence 6?

— ExhibitC

Sentence 6:In addition, I have took a number of manufacturing-related courses, including collective bargaining, labor problems, and research methods.

Which correction should be made to sentence 6?
A . replace In addition with Also in addition
B . change took to taken
C . change took to had took
D . insert a comma after including
E . no correction is necessary

Answer: B