Which of the following sentences contains at least one error?
a. Congress's efforts to get the legislation passed were stymied by the president's veto.
b. The search committee is finding it extremely difficult to narrow down the list of job candidates to five.
c. The school board has been accused of disregarding its responsibilities by failing to provide sufficient oversight of the city's schools.
d. The job candidate did good in the math assessment, but showed deficiency in oral communication skills.