The correct historical figure is 27 years — Nelson Mandela was imprisoned from 1962 to 1990, most of it on Robben Island.

Note: The number 27 does not appear among the given options, so this question appears to be defective. Of the choices, (D) twenty-nine is the nearest.

Please follow the official answer key of your board for this question.

What to remember: Mandela gave up his family, his career as an attorney and nearly three decades of his life for the freedom of his people, and became South Africa's first black President in 1994.