Could someone explain why B is correct while others are not?
First of all, good to see you back Kpadma
A) improperly compares "manage and maintain" to "other types of investments"
B) paper assets are much easier to manage and maintain than are other types of investments --> proper comparison [paper assets are / other types of investments (are)]
C) same error as in A
D) same error as in A
E) needs plural form "are" instead of "is" to make proper comparison