English

The phrase 'next stage of his training' is more appropriate in this context because 'stage' refers to a broader phase or period within a training program. 'Step' typically refers to a specific action or milestone within a process, which is more immediate and task-oriented. Since the sentence implies progression through phases of training, 'stage' fits better. Therefore, the correct answer is 'D' (stage).

The word 'disparity' means a great difference or inequality between two or more things. Therefore, 'difference' is the correct synonym among the options provided.

The word "frugality" means the quality of being economical or thrifty with resources. Among the options, "thrift" is the synonym that best matches this meaning, while the others have unrelated meanings.

The word "stodgy" means dull, boring, or old-fashioned, so the synonym "dull" correctly matches its meaning. Other options like "sturdy," "blunt," and "obstinate" do not convey the same sense.

The word "inexplicable" means something that cannot be explained or understood. "Unexplainable" is a direct synonym, making option C the correct answer.

The word 'adversity' means difficulties or misfortune, so its synonym is 'hardship'. The other options do not share this meaning.

The word "variegate" means to diversify in appearance, especially by marking with different colors. Therefore, "multi-color" is the correct synonym among the options provided.

The word "serene" means calm, peaceful, and untroubled. Among the options, "calm" is the closest synonym, making option D correct.

An embargo is an official ban or prohibition on trade or other commercial activity with a particular country. Therefore, 'prohibition' is the correct synonym.

The word "prognosis" refers to a forecast or prediction, especially about the likely course of a disease or situation. Among the options, "forecast" is the closest synonym, making option B correct.