The exact value of $M_C$ cannot be determined without knowing the individual elements of datasets $A$ and $B$.

The combined median $M_C$ must lie in the range $[15, 25]$.

The combined median $M_C$ is exactly the average of the two medians, which is $\frac{15 + 25}{2} = 20$.

The combined median $M_C$ is guaranteed to be greater than $25$ because dataset $B$ has more elements than dataset $A$.