Which directory in Oracle Applications R12 contains ORA…

Which directory in Oracle Applications R12 contains ORACLE_HOME used for the tools components of the
Applications technology stack?

A.
apps/tech_st/8.1.7

B.
apps/tech_st/8.0.6

C.
apps/tech_st/10.1.3

D.
apps/tech_st/10.1.2

E.
apps/tech_st/10.2.0