<em>The orchard walls are high and hard to climb, And the place death, considering who thou art, If </em><em>any</em><em> of my kinsmen find thee here.</em>
<em>Any</em> is the indefinite pronoun because it means something like "it does not matter who of my kinsmen as long as the person is one of my kinsmen" although Present Day English demands agreement as third person singular (<em>if any of you agree</em><em>s</em>) in the passage the agreement is third person plural because from the point of view of meaning [<em>any of my kinsmen</em>] can be replaced as <em>they</em>  and the verb <em>find</em> agrees with this plural idea.
Present Day British English has this kind of agreement called collective noun which grammatically can function like the pronoun <em>they</em>, for example as in <em>the committee </em><em>have</em><em> started the meeting</em>). The word <em>police</em> is another example of collective noun by taking third person plural agreement as in the sentence <em>The police </em><em>have </em><em>arrived</em>.
 
        
             
        
        
        
Answer:
The single set of factors that best explain their responses is *Life-cycle factors*
Explanation:
Life cycle are stages we pass through out our lifetime as humans.
The choices of individuals are always different based on their life-cycle factors, especially with children. Life cycle factors are factors for assessing individuals choices or alternatives based on their age and present state of mind.
Though 4-year-old Fernando is very happy as he is still in adolescence stage which makes the transition very easy for him, while 13-year-old Jorge is quite unhappy, considering her age, there is a tendency she might have a very difficult time adjusting to the move.
The factors which determines their decision are their life-cycle factors.