Writing: Possessive Pronouns — Basic example

Ilana and Phyllis couldn't find the keys to their spaceship which Phyllis insisted she had hung on a peg in the workshop all right so there is underlined this is a possessive pronouns question so let's go through the options no change there th e ir her or th ER e so right out of the gate I'm gonna say a nun no change let me tell you why there is a very common error for their their their confusion sure there is they in this referring to Alana and Phyllis but th ey apostrophe r e is a contraction of they are and we know that we're talking about the spaceship that belongs to Alana and Phyllis so we know that this is not the right word th ey apostrophe r e they are spaceship no good so let's cross that off there th e ir that's the possessive form that looks great to me but let's keep moving her her is tempting because maybe the spaceship belongs to one of them however that's less correct than there because it creates a pronoun clarity error right which person does it belong to - Sybil on - Alanna or does it belong to Phyllis we don't know that and we can't know that from the sentence so we're gonna have to eliminate it although I understand why it's tempting finally th ER e well this is an adverb right the spaceship was there in the workshop so it doesn't work what we're looking for is a possessive pronoun that pronoun that behaves like an adjective that says this spaceship belongs to Alanna and Phyllis so it's not going to be there so that leaves us with option B th e IR because it applies to both Alanna and Phyllis it belongs to them it is theirs it is their spaceship