Read each sentence and select the three choices that should be followed by a colon.

By personal opinion, if you HAVE to put a colon, I would put it after approached, following, and cultures. :)
Each lead to a subject that is listed in the sentence.
Answer:
Colons and semi-colons are breaks within sentences, stronger than a comma but not a full stop; due the need to separate 2 or more independent clauses, especially if the subsequent clauses explain, emphasizes, sharpens, summarizes or illustrate the first one and both are closely related.
Thereby:
1. One thought...as Friday approached: "Please let this week be over."
2. Thomas Jefferson...included the following: life, liberty, and the pursuit of happiness.
3. Ander's family...different cultures: his mother's...Swedish, while his...Brazilian.
Explanation: