Areference in a text to another well known text person event or thing is called an?

What is the tone of this passage from andrew jackson's message to congress? "the consequences of a speedy removal will be important to the united states, to individual states, and to the indians themselves. the pecuniary advantages which it promises to the government are the least of its recommendations. it puts an end to all possible danger of collision between the authorities of the general and state governments on account of the indians." andrew jackson, annual message to congress on december 6, 1830" a. ashamed and apologetic b. intelligent and professional c. bitter and jealous d. entertaining and humorous