Which Molecule Produces the Strong Absorption Bands in the Spectrum

Multiple Choice

Which molecule produces the strong absorption bands in the spectrum of a cool M-type star,as can be seen in Figure 10-5 of Comins,Discovering the Essential Universe,6th ed.?

A) HCl, hydrogen chloride
B) CaI, calcium iodide
C) H₂O, water vapor
D) TiO, titanium oxide