Vacancies in the company will be notified by .....

The word that best completes the sentence is "advertisement." The word "advertisement" is the most appropriate option in the context of notifying vacancies in the company to the public. It refers to a paid promotion or notice in a medium such as newspapers, websites, or social media. Companies typically use advertisements to attract the attention of job seekers and notify them of job openings. The other options provided could also be used in some contexts, but they do not specifically convey the idea of job vacancies. For instance, "bulletin" is a general term for a brief announcement or report of recent events, while "publication" refers to a printed or online material that contains articles, stories, or other content. "Publicity" typically refers to the act of promoting or advertising something to the public, without necessarily indicating that there are job vacancies available.