What technological solutions have already been tried? What have the results been? How does this compare with solutions that you have researched or learned about in your study of the unit
problem?

it's false. hope i .

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.