B) to assure himself of its truth
The options given have you take a closer look at the words it's and himself. Option C changes "himself" to "hisself". "Hisself" is never correct. This means we have to decide if the correct answer is "its" or "it's". "Its", without an apostrophe, is the possessive form showing ownership. "It's", with an apostrophe, is a contraction meaning "it is". Let's plug them into the sentence "of it is truth" does not make any sense. Can "it" own truth? Yes, so "its" is the correct answer.
D. The enemy is crafty, unscrupulous, experienced in deception.
This is the best choice. By calling the enemy crafty, unscrupulous, experienced in deception, Stalin is feeding the hatred the people have for the enemy. He is detailing the traits that are not desired and makes the people feel as though they are justified in their efforts to defeat the enemy. These details are also insulting to the enemy and could also be used to incite the enemy.
Beneath the deep blue sea
D because it says that he was mad AS hell. A simile uses like or as.