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 .

OPTIONS: A). None of the above choices .. B). They know Mary ca n't run away now .. C). They know how much Joe loves Mary .. D). They know how much Mary loves their family ..
Answer the following question: What may be the reason for the family being so happy about the engagement ?
C).