The diagram shows the structure of compound A. In compound A, some carbon atoms are arranged tetrahedrally around their bonds. Other carbon atoms in compound A have a trigonal planar bond arrangement. How many carbon atoms are there of each type?
- Atetrahedral $5$, trigonal planar $12$
- Btetrahedral $8$, trigonal planar $8$
- Ctetrahedral $9$, trigonal planar $6$
- Dtetrahedral $9$, trigonal planar $8$