Answer: A
Cleavage by HIOX4 requires a vicinal diol, which excludes butane-1,4-diol. Butane-1,2-diol gives HCHO and propanal, and 2-methylpropane-1,2-diol gives HCHO and propanone, i.e. two different products. Only symmetrical butane-2,3-diol gives a single product, 2 CHX3CHO, which is Tollens and iodoform positive.