What is the object of the preposition in sentence?

Question

Scrooge will walk alone from his offices.
A. alone
B. Scrooge
C. walk
D. offices
My answer is a. I'm I correct?

Answer 1

No.

http://www.grammar-monster.com/lessons/prepositions.htm

Answer 2

Reed that's no help. No one feels like reading that, the answer is D. Office.

Answer 3

Thank you Reed.

Answer 4

i feel like reed might be a teacher