The expression "to burn the candle at both ends" means to work or exert oneself continuously without rest, often to the point of exhaustion. It implies overworking or using energy excessively, typically in both early morning and late night hours.
Option (2) "to work hard continuously" accurately describes the meaning of the idiom. It refers to putting in a lot of effort, especially without taking breaks.
Option (3) "to strive hard" is also relevant, as it suggests working with great effort, though it's not as specific as the idea of continuous work.
Option (4) "to spend lavishly" can also apply to the idiom in a figurative sense, where overexertion or draining resources (such as time and energy) might be implied. However, it's less common.
Option (1) "to succeed slowly" does not reflect the idea of overworking and is incorrect.
Conclusion:
The correct interpretation of "to burn the candle at both ends" includes options (2), (3), and (4), all of which can reflect the act of excessive effort or consumption.