Answer:
Okay so we know that pOH + pH = 14, so if pOH is 0.253 the pH would be 13.747.
And pH = -log [H+], so [H+] = 10^(-pH) -->This is just the antillog...
so [H+] = 1.791e-14, which would make sense for the strongly basic solution (so B is the correct answer)
Hope this helps...