Which language is used by OBIEE to query Essbase?

Which language is used by OBIEE to query Essbase?

A.
SQL

B.
LINQ

C.
MDX

D.
DMX

Explanation:
The Essbase cube looks just like any other relational star schema in my
Presentation Layer, however when it is queried Oracle BI Server will issue MDX queries against a
multi-dimensional data source, rather than an SQL query against a relational star schema.