Explain how the action of a peptide hormone is similar to the action of the neurotransmitter norepinephrine.

While norepinephrine is majorly a neurotransmitter (in synaptic transmission) , it also acts as a hormone produced by the adrenal gland. It is usually secreted as a stress hormone, just like cortisol. It increases heart rate,  blood flow in skeletal muscles, production of glucose by the liver, especially in the fight-or-flight response.

the correct answer is option d.

an appositive is a noun, noun phrase or noun clause which follows another noun or noun phrase in order to describe it or name it another way. they are usually used between commas, brackets or dashes.

the example sentence with the correct use of commas is the following:

her uncle, the man over there in the red shirt, owns the hardware store in town.