If channel length modulation is present. what is the overall output impedance of the following CG stage?

• A. Rd || {Rs*(1+gm * ro) + ro}
• B. Rd || {Rs*(1+gm * ro) + 2ro}
• C. Rd || {Rs*(1+gm * ro) – ro}
• D. Rd || {Rs*(2+gm * ro) + ro}