I just got home from my Mom 's where we had a big labor day picnic with too much food as usual . The Labor Day party ended up turning into an engagement party because my little brother , Joe , proposed to his girlfriend , Mary , on Saturday . We are all very happy and excited for them . They dated while they were in high school , then broke up when Mary went away to college . Joe would never admit it , but he was heartbroken , and never had another serious girlfriend .
According to the above context, choose the best option to answer the following question.
Question: What may be the reason for the family being so happy about the engagement ?
Options:
- None of the above choices .
 - They know Mary ca n't run away now .
 - They know how much Joe loves Mary .
 - They know how much Mary loves their family .


They know how much Joe loves Mary .