Question 1 is Tampoco Question 2 is Ninguno
The right answer is:
"Yo trabajo en mi tarea".
That´s because is talking in first person.
"Trabajas" is for "you".
"Trabajan is for "they"
and "Trabajamos" is for "we"
En la Mano because unas means means nails
En la Mano = in the hand
En la cabeza = in the head
En la pierna = on the leg
En el corazon= in the heart