The number of Wodehouses works that feature a character

IMO A

BD are identical, so cant be correct. Also use of these is incorrect.
CE are wrong because of use of 'are' as the number is singular. Hence, SVA error

A) that feature a character named Rollo is quite large, and in most of them the protagonist is an amiable and indolent character who blunders happily

B) that feature a character named Rollo is quite large, and in most of these the protagonist is an amiable and indolent character who blunders happily

C) that feature a character named Rollo are quite large, and in most of them the protagonist is an amiable and indolent character who blunders happily

D) that feature a character named Rollo is quite large, and in most of these the protagonist is an amiable and indolent character who blunders happily

E) , which feature a character named Rollo, are quite large, and in most of them the protagonist is an amiable and indolent character who blunders happily

The number ... is always singular so 'is' usage is correct
eliminate options C/E ;

A) that feature a character named Rollo is quite large, and in most of them the protagonist is an amiable and indolent character who blunders happily
; correct choice as most of them refers to Wodehouse's works ..

B) that feature a character named Rollo is quite large, and in most of these the protagonist is an amiable and indolent character who blunders happily
in most of these ; is wrong usage

generis option B&D are similar

OPTION A is correct

D) that feature a character named Rollo is quite large, and in most of these the protagonist is an amiable and indolent character who blunders happily same issue as B