Objects in the image:
category: person
category: tennis racket
category: person
category: person
category: person
category: person
category: person
category: tennis racket
category: person

Guessing-game dialogue about one of the objects:
q: a person??
a: Yes
q: one of the 2 players?
a: No
q: ball boy in the left?
a: No
q: wearing red?
a: Yes
q: one of the three persons behind the green player?
a: Yes
q: the one on the right?
a: No
q: in the middle?
a: Yes