Identify the correct order of acidity of hydrides of $16^{\text {th }}$ group elements from the following.

The acidity of hydrides of Group 16 elements increases down the group. This trend arises due to decreasing bond dissociation enthalpy of the E–H bond as atomic size increases from oxygen to tellurium.

Atomic radii follow O < S < Se < Te, resulting in bond lengths O–H < S–H < Se–H < Te–H. Consequently, bond strengths decrease in the order O–H > S–H > Se–H > Te–H. Weaker E–H bonds facilitate proton donation, making the hydrides more acidic down the group.

The acidity order is $H_2O < H_2S < H_2Se < H_2Te$, or equivalently $H_2Te > H_2Se > H_2S > H_2O$. Among the options, only C matches this sequence.

Final answer: $\boxed{\text{C}}$