Which of the following phrases (I), (II), and (III) given below each sentence should replace the phrase printed in bold letters to make the sentence grammatically correct? Choose the best option among the five given alternatives that reflect the correct use of phrase in the context of the grammatically correct sentence. If the sentence is correct as it is, mark (e) i.e., "No correction required" as the answer.
Every Open House we held since 2013 reaffirmed our belief that there is a need for human intervention to retain its trust and credibility over the age of anonymous communication.
(I)to retain trust and credibility in this age of
(II)to retaining trust and credibility ageing
(III)for retention of trust and credible age of
(a) Only (I) is correct
(b) Only (III) is correct
(c) Both (I) and (II) are correct
(d) Both (II) and (III) are correct
(e) No correction required
Only a is cirreco