Select the most appropriate word to fill in the blank.
It is well known that the company is ___________ against older workers and refuses to hire anyone over the age of 50.

The correct option is (a) prejudiced.
Explanation: The correct form of the word here is "prejudiced," which means to have a bias or unfair opinion against someone. The sentence needs the adjective "prejudiced" to describe the company's stance.
Meanings of all options:
· Prejudiced: Having or showing bias or unfair opinions against someone.
· Prejudicing: Present participle form, showing the action of being biased, which doesn't fit the sentence structure.
· Prejudices: Noun or verb form, does not fit as the sentence requires an adjective.
· Prejudice: Noun or verb, does not fit in this context.
Correct sentence: "It is well known that the company is prejudiced against older workers and refuses to hire anyone over the age of 50."