If I1 and I2 are two intensities in watts per square centimetre, then the number of decibels with which they are related can be expressed as _________

If I1 and I2 are two intensities in watts per square centimetre, then

1.	If I1 and I2 are two intensities in watts per square centimetre, then the number of decibels with which they are related can be expressed as _________
A.	N = 10 log I1/I2
B.	N = 10 log I2/I1
C.	N = -10 log I1/I2
D.	N = log I1/I2
Answer» B. N = 10 log I2/I1