The correct answer is Very young owls grow slowly.
Here, the adverb is <em>very </em>and the adjective is <em>young, </em>so the adverb is used to modify the adjective, or to show a particular degree of the adjective (how young? very young.).
In the rest of the options, there is only one adverb <em>slowly, </em>and it's not modifying an adjective, but rather the verb.
Answer:
D. Doris discovers that her father brought the dog back
Explanation:
A would be the answer, Tomas was frustrated during class he forgot his book report. I believe there should be a comma in between class and he