The correct option is B careful
The given passage speaks about moral courage and physical courage. The adjoining question asks what the man of moral courage might be, and from the given options, 'careful' is the most suitable option. A man of moral courage might be careful, this is suggested by the line "I have seen men who undoubtedly possessed moral courage but were very cautious about taking physical risks". The word 'careful' means the same as 'cautious', they both mean 'to avoid potential dangers', hence it's the right answer, and option A is correct. Option B is incorrect because none of the statements concerning moral courage mention 'intelligence', or something synonymous to it. "A more reasoning attitude which enables him to take coolly his career... is moral courage". This sentence talks about one's reasoning, which is not the same as being 'intelligent'. 'Curious' or any word synonymous to it that concerns the topic of 'moral courage', is not mentioned in the passage. Moral courage is about being able to reason with something, having a value system as suggested in "a more reasoning attitude which enables him to take coolly his career...or his judgement of what he thinks either right or worthwhile, is moral courage". Hence option C is incorrect. Similarly, 'cunning' is not suggested by the passage at all that concerns moral courage. It's quite the opposite, moral courage concerns a value system that distinguishes between right and wrong, hence option D is incorrect.