If g is the transconductance, r is the resistance due to channel length modulation and if M2 and M1 has channel length modulation but M3 doesn’t, what is the total voltage gain for only M2?

• A. g * {(1 + gr)* (R || 1/g || r) + (R || 1/g || r)} || R
• B. g * {(1 + gr)* R + R} || 4R
• C. g * {(1 + gr)* R + 3R} || 4R
• D. g * {(1 + 2gr)* R + R} || 4R