[单选题]
The intensity at a distance of 6.0 m fgsg6:1zaf mu/1a g-7cr3v i krrom a source that is radiating equally if3x -t fgzanup0r s8ow29:*g kn all directiont:0kz-ofg 2 wsa3rn9x8*fpug s is $6.0 \times 10^{-10} \; W/m^{2}$. What is the intensity level in dB?
A. $18 \; dB$
B. $23 \; dB$
C. $28 \; dB$
D. $32 \; dB$
