I met an old friend of mine .
A. on my way to home B. in my way home
C. in my way to home 
D. on my way home
I met an old friend of mine .
A. on my way to home B. in my way home
C. in my way to home D. on my way home
D 考查固定短语。on one’s way to意为“在某人去……的路上”。home在此作副词，因此to要省略。故答案为D。