Answer: B. 80
Exactly two = (25-10)+(20-10)+(15-10)=15+10+5=30. Exactly three=10. Total=150. Exactly one = 150 - 30 - 10 = 110. But options don't have 110. I need to adjust. Let me set: M=60, E=50, N=40, M&E=20, E&N=15, M&N=10, all=5. Then exactly two = (20-5)+(15-5)+(10-5)=15+10+5=30, exactly three=5, total=150, exactly one=150-30-5=115. Still not. Let me set total=100. Then exactly one=100-30-5=65. Not. Let me set total=80. Then exactly one=80-30-5=45. Not. Let me set total=120. Then exactly one=120-30-5=85. Not. Let me set total=130. Then exactly one=130-30-5=95. Not. Let me set total=140. Then exactly one=140-30-5=105. Not. Let me set total=160. Then exactly one=160-30-5=125. Not. Let me set total=170. Then exactly one=170-30-5=135. Not. Let me set total=180. Then exactly one=180-30-5=145. Not. Let me set total=190. Then exactly one=190-30-5=155. Not. Let me set total=200. Then exactly one=200-30-5=165. Not. So I need to choose numbers such that exactly one is in options. Let me set: M=50, E=40, N=30, M&E=20, E&N=15, M&N=10, all=5. Then exactly two = (20-5)+(15-5)+(10-5)=15+10+5=30, exactly three=5, total=100, exactly one=100-30-5=65. Not in options. Let me set: M=60, E=50, N=40, M&E=25, E&N=20, M&N=15, all=10. Then exactly two = (25-10)+(20-10)+(15-10)=15+10+5=30, exactly three=10, total=120, exactly one=120-30-10=80. That gives 80, which is option 2. So I'll use these numbers. So question: total=120, M=60, E=50, N=40, M&E=25, E&N=20, M&N=15, all=10. Then exactly one=80. answer_index=2. I'll update.