Select the option that arranges sentences A, B, C and D in a logical sequence.
A. But unfortunately, this so-called best friend has turned a foe.
B. These changes can produce fatigue, dizziness and loss of concentration.
C. The cell phone has now usurped the dog's place to become man's best friend.
D. Research studies have concluded that the microwave frequencies penetrating the heads of cell phone users can cause adverse neurological changes.