The correct answer is D. praises himself.
A man who blows his own trumpet is someone who constantly talks about his own achievements and abilities. He is often seen as arrogant and boastful, and people may not trust him because they believe he is exaggerating his own importance.
Option A, flatters, is incorrect because a man who blows his own trumpet is not trying to make others feel good about themselves. He is only interested in making himself look good.
Option B, praises others, is incorrect because a man who blows his own trumpet is not interested in praising others. He is only interested in praising himself.
Option C, admonishes others, is incorrect because a man who blows his own trumpet is not interested in admonishing others. He is only interested in praising himself.