Place the following in the sequence of the progression of HIV/AIDS on a cellular level.
1)The HIV virus is uncoded.
2)HIV attaches to the receptors on the CD4+ cell.
3)DNA synthesis occurs by reverse transcription.
4)Transcription of the DNA to form a single-strand messenger RNA.
a) 3,4,1,2,
b) 2,1,3,4
c) 1,2,3,4
d) 4,3,1,2