Why is it B and not C

Here is the question:

[

11 Hydrated chromium(III) chloride, CrCl3.6H2O, exists in several isomeric forms with varying numbers of chloro and water ligands.

A solution containing 0.10 mol of one of these isomers reacts with excess silver nitrate. 0.20 mol of silver chloride, AgCl, is precipitated immediately.
The formula of the complex ion in this isomer is

A [Cr(H2O)6]3+
B [CrCl(H2O)5]2+
C [CrCl2(H2O)4]+
D [CrCl3(H2O)3]

]

In the mark scheme the answer is B.

I think it is C because 1 molecule of the complex should provide 2 atoms of Cl to give the 0.1:0.2 ratio given between the complex and the AgCl.

What am I missing?

Thanks in advance!

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