Answer:
3 - Photoreceptors.
Explanation:
Photoreceptors are a sensor that is connected to your retina. They sense light and send the message to your brain. The sensors automatically squint your eyes if something will blind you.
The correct answer is 'photoreceptors'.
Doctors have not identified a specific cause or result but they think that there are risk factors like:
- advancing age
- family history
-umheathly life style choices
- taking certain medicine
and just in case you did not know what osteoporosis is it is a common disease that weaken the bone and as they weaken you have a higher risk of unexpected fractures
