Your question is incomplete because you have not provided the underlined section. The complete sentence is:
The recently built children’s amusement park has been called "a boon to the community" by its supporters and "an eyesore" by its harshest critics.
Answer:
a.and "an eyesore" by its harshest
Explanation:
The sentence is correct because it is not necessary to separate and from the quotation with a comma or dashes, or to separate the quotation from its original speakers - its harshest critics. Besides, both quotations are embedded in the sentence, which mentions the opinion of the supporters and critics of thh amusement park. In fact, the first quotation. "a boon to the community," does not contain any commas or dashes.
