Since $\mathrm{A}$ and $\mathrm{B}$ are select lines, check the function for each fixed value of $\mathrm{A}\mathrm{B}$.
For $\mathrm{A}\mathrm{B}=00$, possible minterms are $m_0$ and $m_1$.
Only $m_1$ is present, so output is $1$ when $\mathrm{C}=1$.
Therefore, $\mathrm{I}_0=\mathrm{C}$.
For $\mathrm{A}\mathrm{B}=01$, possible minterms are $m_2$ and $m_3$.
Only $m_2$ is present, so output is $1$ when $\mathrm{C}=0$.
Therefore, $\mathrm{I}_1=\mathrm{C}'$.
For $\mathrm{A}\mathrm{B}=10$, possible minterms are $m_4$ and $m_5$.
Only $m_5$ is present, so output is $1$ when $\mathrm{C}=1$.
Therefore, $\mathrm{I}_2=\mathrm{C}$.
For $\mathrm{A}\mathrm{B}=11$, possible minterms are $m_6$ and $m_7$.
Only $m_7$ is present, so output is $1$ when $\mathrm{C}=1$.
Therefore, $\mathrm{I}_3=\mathrm{C}$.

Answer: C