If cars A & B have to be placed adjacent to each other, we have to make sure two spots right next to each other are given to them.
St 1 -
B & C are in even places like 2&4 or 4&6 or 2&6
Only 2nd position matters - in which case, if B is at 2, A can be at 1 or 3
Thus, F can be in 1st position or not
Not sufficient
St 2 -
D & E are in odd places like 1 & 3 or 3 & 5 or 1 & 5
In 1 & 3 case -> automatically F's position isn't at 1st parking lot since its been given to D or E
In 3 & 5 case -> since A & B have to be adjacent to each other, they can be given 1 & 2 positions only -> automatically F isn't at 1st lot space
In 1 & 5 case -> automatically F isn't allotted 1st place since its taken over by D or E
Thus in all cases F isn't in 1st parking lot
Hence B is the answer!