Obstetrics, with its unusually high malpractice insurance premiums, rates among the most expensive medical specialties for doctors to practice, eclipsed only by various forms of surgery.
A. rates among the most expensive medical specialties for doctors to practice, eclipsed only ->
Correct;
eclipsed only by ... is acting as a Noun + Noun modifier and can modify noun or clause. B. rate among the most expensive medical specialties for doctors to practice, only eclipsed ->
Obstetrics is singular as is suggested by its in non-underlined part, hence rate will be IncorrectC. has a rating among the most expensive medical specialties, only eclipsed ->
only eclipsed change the meaning, has a rating is awkward -
IncorrectD. are among the most expensive medical specialties for doctors to practice, eclipsed only ->
are is incorrect as is suggested in option B -
IncorrectE. have been rated among the most expensive medical specialties for doctors to practice, only eclipse ->
have been plural is IncorrectAnswer - A