Respuesta :
I think it is either A or B... I am leaning towards B because Lesquels is the plural of Lequel (at least I think it is), and this question is referring to multiple people with the word 'they'
Bonjour
WHICH ONE do they prefer ?
lequel préfèrent-ils ?
Explanation :
lequel is masc. singular as "which one "
it could have been "laquelle" (feminine singular) as well
IT HAS TO BE SINGULAR
lesquels = which ones (masc. & fem. plural)
auxquels = à+ lesquels - contraction (masc. plural)
desquels = de+ lesquels - contraction (masc. plural)
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