Answer:
b. la cuchara
Explanation:
Assuming here you talk about the general, more global, term of sopa... which generally means "soup", and not the sopa that is a tostada with toppings in some countries like Mexico and Guatemala, this one you just eat with your hands.
You eat the soup with a spoon (cuchara) like everyone else. It would be quite complicated to eat the soup with a fork (tenedor) even if some soups have big pieces of meat or veggies in it.
You could use a glass (vaso) but then you would drink your soup, not eat it.
