Answer:
A.
Step-by-step explanation:
A is incorrect. The definition of logarithms is that if
, then
.
The variables are in the wrong place. The correct answer should be:

B is correct since as
. Thus, 
C is correct because the square root of anything is simply that thing to the one-half power.
D is also correct as this is <em>the </em>definition of a logarithm.