In the following question, two statements are given with some words in bold. Which of the following pairs of bold words must be interchanged to make both the sentences grammatically correct.

a. Marx has been (A)described as one of the most (B)influential figures in human (C)history, and his work has been both (D)citing and criticised.

b. During his (E)presidency, Trump ordered a travel (F)ban on citizens from several Muslim-majority countries, (G)lauded security (H)concerns.