Please help me is it a or an

Which one of the following is a trick used in spanish to identify the right hand? touch the tips of your index fingers with the tips of your thumbs. the hand that forms a lowercase b is your mano derecha. touch the tips of your index fingers with the tips of your thumbs. the hand that forms a lowercase d is your mano izquierda. touch the tips of your index fingers with the tips of your thumbs. the hand that forms a lowercase d is your mano derecha.

¿debo pedir comida a la habitación? a. es buena idea que pidas comida a la habitación. b. es buena idea que pedir comida a la habitación. c. es buena idea que pediremos comida a la habitación.

Need with this match the pronoun with the sentence it belongs to: )