"How can a human being with any claim to a sense of moral responsibility deliberately let loose an instrument of destruction which can at one stroke annihilate an appalling segment of mankind? This is not war: this is not even murder; this is pure nihilism. This is a crime against God and humanity which strikes at the very basis of moral existence. What meaning is there in any international law, in any rule of human conduct, in any concept of right and wrong, if the very foundations of morality are to be overthrown as the use of this instrument of total destruction threatens to do?" — Nippon Times (Tokyo), August 10, 1945.
What does the author mean by saying that dropping a nuclear bomb "strikes at the very basis of moral existence?"

He means that the moral values of human race is lowered with the dropping of nuclear bombs.

Explanation:

In the given excerpt, the author is addressing the dropping of the atomic bombs on Hiroshima and Nagasaki by the U.S. The writer considers that the dropping of the atomic bomb was not on Hiroshima and Nagasaki but the moral values of the human race.

The writer writes that these droppings are not a crime against humankind but God. By dropping the atomic bomb, the humans have stooped so low that it has shaken the very basis of a moral existence. The foundations of morality are overthrown with the use of such a destructive instrument as an atom bomb.

the answer to this question is d

the secretary of state, appointed by the president with the advice and consent of the senate, is the president's chief foreign affairs adviser. the secretary carries out the president's foreign policies through the state department and the foreign service of the united states.