The correct answer is Option C. A classified advertisement is the
most common type of advertisement in a news paper where the
advertisements are placed under specified headings. They have limited
space and specific information and are charged accordingly. So, 'Vacancy for the post of senior executive at your office' would be written as a 'classified
advertisement'.
Option A is incorrect as a headline gives us a overview of an article.
Option B is incorrect as a poster is used to provide information or promotion in an eye-catchy manner.
Option D is incorrect as a non-classified advertisement or a display
advertisement do not have any specified page or a heading and there is
no limitation of space for the advertiser.