Which of the following is closest in meaning to the statement “There are various...

Which of the following is closest in meaning to the statement “There are various... to do so” (Line 17-20)?

［A］ Principles of history and philosophy are hard to deal with.

［B］ People like to see what other people do for their own model.

［C］ The educated are more susceptible to errors in their daily life.

［D］ That everyone does the same may not prove they are all right.