Answer:
C, 15.35 cm
Explanation:
By the definition of a perpendicular bisector, AD is equal to DB. This means that AD is half of AB. Thus;
AD = 4.5 cm
DB = 4.5 cm
It is given that AC is 16 cm and that Triangle CDA is a right triangle. By the Pythagorean Theorem:

Simplify:

So the correct answer is 15.35 cm.