“Congenial “ means pleasant or agreeable because suited to one's taste or inclination.
Option A is the correct answer because “suited” means right or appropriate for a particular person, hence it is the right meaning for the given word.
Option B is incorrect because “beneficial” means resulting in good; favourable or advantageous, which is not particularly correct for “congenial” as a meaning hence it is incorrect.
Option C is incorrect because “helpful” means being of great help or having a helping nature, which is not the suitable meaning for congenial, hence incorrect.
Option D is incorrect because “partial” means existing only in part, incomplete, which is not the correct meaning for congenial, hence it is incorrect.