The most stable enolic from of 2, 4-pentanedione is :
A. `CH_(2)=overset(OH)overset(|)(CH-CH_(2))-overset(O)overset(||)(C)-CH_(3)`
B. `CH_(3)-overset(OH)overset(|)(C)=CH-overset(O)overset(||)(C)-CH_(3)`
C. `CH_(2)=underset(OH)underset(|)(CH)-underset(OH)underset(|)(CH)=CH_(2)`
D. `CH_(3)-underset(OH)underset(|)(C)=C=underset(OH)underset(|)(C)-CH_(3)`
