Q:Read the following article and select the best answer. Article: 1 On Friday, January 14, 2005, my cousin, Kara Rose, came into the world. 2 She looked perfectly healthy from the outside, but on the inside, the doctors had failed to discover a serious problem. 3 She often had trouble breathing and then turned blue. 4 The doctors found that Kara had been born without part of her heart. 5 They didn't think she would live long enough to leave the hospital. 6 When she was four days old, she had her first operation. 7 My family stayed together during this hard time, hoping everything would turn out for the best. Kara's strength and determination to live were strong. Eventually, she could go home. We all waited patiently for new technology that could give Kara a new heart. When she was eighteen months old, her parents took her to a famous surgeon who performed a series of operations. There was no guarantee she would make it through the operation, but she succeeded. Kara grew stronger every day, and it was not long before she was well enough to be around people. She had an amazing character and always wore a sweet smile. When she fell asleep against my body, happy and content, I realized how valuable life really is. As I took her in my arms with her warm breath against my neck, I decided to live every day of my life to the fullest. This child, who is 15 years younger than I, has gone through more suffering and pain than I ever have. I admire her strength and determination. Kara has taught me that no matter how bad things seem, they can work out in the end. Knowing this small, beautiful child has made me a stronger person, I now believe that difficulty can be beaten. Question: Kara often had trouble breathing because _ . - she didn't stay long enough in the hospital - the doctors failed to discover the problem - she was born with an incomplete heart - her first operation was not successful
A:
she was born with an incomplete heart