Es su piñata , es mi regalo, es mi camara, son sus globos
You want to do partying that is what it is translated to english
Elena b. está en la tienda.
For location, you should use the verb estar, so that rules out options B, es, and D, son, as they are forms of ser. Choice A, estoy, is conjugated for 'I, so you know that is incorrect as well. This leaves only est<span>á as the correct word.</span>