Respuesta :
the correct answer actualy is...
B. When phones had chords
just took the quiz hope this helps :)
Answer: when phones had cords
Explanation: This relative clause functions as an adjective because it modifies the noun "days" in a defining way (i.e., the detail that phones had cords is essential in defining "days"); remembers the days and "had cords" are just verb phrases taking an object, while "My mom remembers the days" is the main, independent clause of the sentence.