PLS HELP ASAP *50PTS*

What is the magnitude (size) of -9.1?
O A. 9.1, because |-9.11 = 9.1
OB. 0.91, because |-9.11 = 0.91
O C.-9.1, because |-9.11 = 9.1
O D. 9.1, because |-9.11 = -9.1