Answer: The correct option is (A) 42.7 units.
Step-by-step explanation: Given that the radius of the circle center at O is 24 units and OC is 11 units.
We are to find the length of chord AB.
We have,
in the right-angled triangle OCB (m∠OCB = 90°),
OB = 24 units and OC = 11 units.
Using Pythagoras theorem in ΔOCB, we have
![OB^2=OC^2+BC^2\\\\\Rightarrow BC=√(OB^2-OC^2)\\\\\Rightarrow BC=√(24^2-11^2)\\\\\Rightarrow BC=√(576-121)\\\\\Rightarrow BC=√(455)\\\\\Rightarrow BC=21.33.](https://img.qammunity.org/2019/formulas/mathematics/middle-school/7yzc5gzzkwnffu213mzi6oxnxw56x15l0a.png)
Since OC is perpendicular to chord AB, so AC = BC.
Therefore, we get
![AB=AC+BC=2* BC=2* 21.33=42.66=42.7.](https://img.qammunity.org/2019/formulas/mathematics/middle-school/qyj4u42qnj9zmt5evtdjpo1hs2e37viax5.png)
Thus, the required length of AB is 42.7 units.
Option (A) is CORRECT.