Which of the Following Is NOT a Strategy Through Which

Which of the following is NOT a strategy through which Russia attempted to expand into the Ottoman Empire?

A) Exploiting its religious ties with Greek Orthodox subjects of the Ottoman Empire to gain influence in internal affairs
B) Allying itself on the basis of common religious and Slavic bonds with Balkan independence movements to become the Great Power patron of potential new states
C) Direct warfare against the armies of the Ottoman Empire
D) All of these were Russian strategies for expansion