Given below is a set of four sentences, and when properly sequenced, form a coherent paragraph. Arrange the sentences in the correct sequence:

a. After the festival, they shook hands, promising to meet again next year.

b. While their teams competed fiercely on the field, off the field they chatted as friends.

c. It was the annual sports festival where business rivals came as spectators.

d. The atmosphere was charged yet friendly, reflecting the spirit of the game.