The correct option is
B Team
In order to fill in the blank with a collective noun, let's understand what a collective noun is. A collective noun is a word that represents a group of people, animals, things etc. For example: The crowd had gone crazy. Here, 'crowd' is a collective noun used to represent people.
Option B - A pair is of two things only. 'Players' can be two or more, hence we can't use 'pair' here. Thus option B is incorrect.
Option C - A bundle can be of clothes, newspapers, books or sticks. Hence, option C is incorrect.
Option D - A pack can be of animals or cards. Hence, option D is incorrect.
Option A - A team can be of players or investigators. Hence, option A is the correct answer.
'A team of players was cheering on the playground.'