Three moles of ${\mathrm{B}}_2{\mathrm{H}}_6$ are completely reacted with methanol. The number of moles of boron containing product formed is 

Amongst the following, the maximum number of compounds which do not behave as Lewis acids are: ${\mathrm{SnCl}}_2, {\mathrm{H}}_3{\mathrm{BO}}_3, {\mathrm{AlCl}}_3,{\mathrm{CF}}_4,{\mathrm{SiF}}_4,{\mathrm{CCl}}_4,{\mathrm{BF}}_3 ,{\mathrm{SnCl}}_4$