Tissue damage activates nociceptors or pain receptors in the skin. A signal is sent to the peripheral nerve to the spinal cord where neurotransmitters or chemical messengers are released. It activates other nerves to pass signal to the brain. The signals are relayed to the somatosensory cortex for sensation, frontal cortex for thinking and limbic system for emotional response.
Answer: C & A
Explanation:
The HOX genes encodes important transcription factors. This factors causes protein to be made that specify cell fate and identify; embryonic primary axis, secondary axis and plays important roles in various tracts development.
I've checked all the options and I think that the right answer looks like this: Mollusks have highly developed olfactory receptors.