Solve 28th one and give proper explanation
Q.28. A mixture of boron trichloride and hydrogen is subjected to silent electric discharge to form 'A' and HCI. 'A' is mixed with $N{H}_3$, and heated to 200$°$C to form 'B'. The formula of 'B' is:
(a) $H_{3}B{O}_3$
(b) $B_2{O}_3$
(c) $B_2{H}_6$
(d) $B_3{N}_3{H}_6$