Answer: C) Apical
Explanation: An epithelium has a free surface, the apical surface, exposed to the outside, and an attached surface, the basal surface, resting on the underlying connective tissue.
There are so many examples for that in different areas, like biology experiment carried out in our lab recently.
Here's one linhttps://www.creative-biogene.com/support/Lentiviral-Vectors-the-Application-for-CAR-T-Therapies
k:
The answer is C I believe
