I was astonished _____ his failure.

I am going _____ home.A. at
B. to
C. towards
D. None

English is quite quirky at times!
‘I’m going home’- No prepositions!
I’m going to my friend’s house/place/pad.
I’m going to office/school/ airport/hospital/college.
Between home and all the other things/nouns mentioned, home is the only noun which isn’t preceded by the preposition ‘to’.
All the things listed above, other than home, are structures with a roof and walls- made of physical objects. They themselves are physical objects, which are tangible, concrete and solid. A home is not. A home is a place we call home. Home is rather an idea. Any place can be home to anyone. ‘He lived in a cardboard box. The box was his home. Rather the box was home to him’.
Or, let me put it this way. All the buildings or names of buildings mentioned above are nouns-only nouns. Just plain nouns. But home? It’s a noun, an adjective, an adverb and also a verb.
So we say ‘I’m going home’. But not ‘I’m going school’ or ‘I’m going airport’. I’m not saying these are the reasons why it’s so. I’m saying, that’s how English works!
The same goes with ‘I’m home’!! No prepositions! It means ‘I’ve reached back home’ or ‘can’t you see that I’m back (from work or a trip overseas ?”:)
‘I’m going home’.
‘Mom, I’m home’.