In most cases, letters of recommendation are required for admission to:

a. junior colleges.
b. community colleges.
c. selective colleges.
d. vocational schools.

The correct option is C.

The recommendation letter helps to complete the profile of an applicant. They provide information about how the student is from the perspective of someone who has worked closely with him during his high school career. The experiences that counselors and teachers have had of him can help paint a better overall picture of his accomplishments, potential and character.

Most selectives colleges and universities requiere one to three letters of recommendation with the application, usually, one from the vocational counselor and at least one teacher.

- He was  carried to the village's foremost occult healer who alone  knew  how to cure  lunatics.

Explanation:

The grammatical structure that is being outlined in the given sentence is 'who alone knew how to cure lunatics.' The relative pronoun 'who' assists in providing information regarding an antecedent or referent mentioned previously i.e. 'foremost occult healer.' Thus, this forms the relative clause followed by an adverbial clause('how to cure lunatics') that functions to provide additional details about the noun and the verb to the reader. Therefore, the underlined grammatical structure is 'who alone knew how to cure lunatics.'