Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Among the entities, try to find the best entity that is most likely to fill in "_" and classify the answers based on options.
Input: When they met in an online IVF support group back in 2011, Andrea Rivas and Sandi Palmisano were two women struggling to get pregnant. They longed for children and believed if they could at least have one healthy baby each, they'd be happy. Fast forward four years and the two women from Martinsburg, West Virginia have six babies between them – three sets of twins. And all of them were carried by Andrea. Their story is a miraculous one of hope and friendship. In 2014 Andrea made headlines when she gave birth to Sandi's children EmmaLee and Grayson after agreeing to become a gestational carrier for Palmisano when a medical condition prevented her from carrying an embryo to term.Andrea Rivas and Sandi Palmisano, both from Martinsburg, W Va, met through an online IVF support groupAndrea, 30, and her husband Mark, 41, had twins through IVF but Sandi, 47, and her husband Philip, 45, failed in three cycles - then Andrea stepped in to become a surrogateBut months after giving birth to Sandi's twins, Andrea and her husband Mark conceived naturally - and amazingly were told they would have twins againShe gave birth in March almost a year to the day since giving birth to Sandi and Philip's twinsSandi tells Daily Mail Online: 'Between the two of us we have six babies. It's almost impossible to put into words.' 
 Questions:But even the doctor was shocked when the ultrasound revealed that _ was having twins, again. (A) IVF (B) Andrea Rivas (C) Sandi Palmisano (D) Martinsburg (E) West Virginia (F) Sandi (G) EmmaLee (H) Grayson (I) Palmisano (J) W Va (K) Mark (L) Philip (M) Daily Mail Online
Output:
(B)