A checkered career means a career marked by both successes and failures or controversies. The correct answer is this meaning because the expression is used figuratively, not only by its literal words.

Examples:

• The politician had a checkered career before becoming a minister.
• In an HSC essay, A checkered career can express this meaning: a career marked by both successes and failures or controversies.
• When this expression appears in a passage, connect A checkered career with the idea of a career marked by both successes and failures or controversies.