Despite of being most efficient method ever, it is still highly inefficient, and this inefficiency inspires hope.

Options

A. Despite being the mostly efficient
B. Despite of being a most efficient
C. Despite of being the most efficient
D. Despite being the most efficient

Answer

D

Explanation

The most appropriate phrase to replace the phrase given in bold is "despite being the most efficient". It is to be noted that "despite" does not take any preposition with it. It is always followed with a noun, pronoun or a gerund. Moreover, when we use a superlative adjective 9most) before the noun, we generally use it with 'the'. This is because there's only one (or one group) of the things we are talking about. Since option (d) is in the precise grammatical syntax, it becomes the most suitable answer choice.