Estan Caminando isn't the answer as because "estan" implies to be another person, but this isn't the case as it's only the man, the man isn't walking (caminando either)
He isn't shopping (comprando) and he isn't painting (pintando)
The only logical answer is he's cooking (cocinando) which is also heavily implied as him having the bowl and whisk
B.) Esta Cocinando is your answer
Question 1:
-Lilliana no juega (al) fútbol americano.
Question 2:
-Usted juega muy bien (a los) juegos de mesa.
Question 3:
-Los muchachos (juegan) al fútbol los sábados.
Question 4:
-MI hermano (juega) con los niños de la escuela.
Question 5:
-Anita y yo (jugamos) al tenis después de clases.
Question 6:
-Girl writing in a notebook: (los dedos)
Question 7:
-Man in white shirt playing tennis: (los brazos y las piernas)
Question 8:
-Girl in white top hitting a volleyball: (los brazos)
Question 9:
-Collage of people performing various dance moves: (el cuerpo)
Question 10:
-Woman playing cards, holding two aces in her hand: (las manos)
I hope that I help you with the answers :) !!