Such lofty dreams can never come true.

The correct answer is A. puny.

A lofty dream is a very ambitious or idealistic dream. Puny means small or insignificant. So, the statement “Such lofty dreams can never come true” means that such ambitious or idealistic dreams are not likely to be achieved.

The other options are not correct because they do not mean “small or insignificant”. Humble means modest or unassuming. Insignificant means not important or noticeable. Casual means relaxed or informal.