Use the most basic forms of english, don't use any complicated words, make sure even a 1st grader could perfectly understand the letter.
They appear as the topic sentences of your paragraphs. I hope I have helped
Answer:
Mr. Hooper had ascended the stairs, and showed himself in the pulpit, face to face with his congregation, except for the black veil. That mysterious emblem was never once withdrawn. ... The veil represents some evil deed hidden in the minister's past that he is afraid to make public.
The answer is the last one, D. All of the other transitions indicate that the writer will either go into further detail on the subject or list other reasons as to why this would be correct. However, D clearly uses a contrasting transition to introduce a new argument.
An unit
A heir
A honest person
A sat score
A yellow hourglass
An ufo
A banana
A x ray
An eagle a bird
A cell a very
An elevator