`V_(1)` mL of NaOH of normality x and `V_(2)` mL of `Ba(OH)_(2)` of normality y are together sufficient to neutralize exactly 100 mL of 0.1 N HCl. If `V_(1) : V_(2) =1 : 4` and if x : y =4 : 1, what fraction of the acid is neutralised by `Ba(OH)_(2)` ?
A. 0.5
B. 0.33
C. 0.67
D. 0.25
