How much memory is available on HP ZBook 15 mobile workstations?

How much memory is available on HP ZBook 15 mobile workstations?

A.
16GB

B.
1.0TB

C.
1.8 TB

D.
2.85 TB

Explanation:
http://h18004.www1.hp.com/products/quickspecs/14722_na/14722_na.pdf