Final answer:
The phrase 'old school tie' refers to a symbol of educational affiliation, often associated with elite institutions, and signifies a network of connections among alumni. Option C
Step-by-step explanation:
The phrase "old school tie" refers to option c) A symbol of educational affiliation. It is commonly used to denote the connections and sense of belonging that alumni of certain prestigious schools, such as Eton, are thought to share.
More broadly, it can imply a network of social or professional connections among former students of any elite institution. The 'old school tie' can be literal, referring to a necktie bearing the school's colors, or metaphorical, signifying the social advantages that the association with the school may afford its alumni. Option C