Official Explanation:
The phrasing in both (A) & (B) are awkward for expressing an action. The idiom "on grounds of X" works best when X is a simple noun, but for a gerund conveying an action, we need a "that" clause.
(C) the double "that" clauses in this is awkward; the rest of the sentence is in the past tense, so the switch the present is unusual here. This is incorrect.
(D) is direct and grammatically correct.
(E) the passive construction is unusual
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